diff --git a/+siibra/+internal/API.m b/+siibra/+internal/API.m
index d3f1b6a..9291c82 100644
--- a/+siibra/+internal/API.m
+++ b/+siibra/+internal/API.m
@@ -79,7 +79,7 @@
 
         function regionsJson = regions(parcellationId)
             absoluteLink = siibra.internal.API.absoluteLinkV3("regions");
-            parameters = ["parcellation_id=" + parcellationId];
+            parameters = "parcellation_id=" + parcellationId;
             regionsJson = siibra.internal.API.collectItemsAcrossPages( ...
                 absoluteLink, parameters);
         end
@@ -124,60 +124,17 @@
             absoluteLink = siibra.internal.API.absoluteLinkV3(relativeLink); 
         end
 
-        function absoluteLink = featuresPageForParcellation(atlasId, parcellationId, page, size)
-            relativeLink = "atlases/" + atlasId + ...
-                            "/parcellations/" + parcellationId + ...
-                            "/features?page=" + page + ...
-                            "&size=" + size;
-            absoluteLink = siibra.internal.API.absoluteLinkV2(relativeLink);
-        end
-        function featureList = featuresForParcellation(atlasId, parcellationId)
-            featureList = {};
-            page = 1;
-            size = 100;
-            firstPage = siibra.internal.API.doWebreadWithLongTimeout( ...
-                siibra.internal.API.featuresPageForParcellation( ...
-                atlasId, ...
-                parcellationId, ...
-                page, ...
-                size)...
-            );
-            totalElements = firstPage.total;
-            featureList{1} = firstPage.items;
-            processedElements = numel(firstPage.items);
-            while processedElements < totalElements
-                page = page + 1;
-                nextPage = siibra.internal.API.doWebreadWithLongTimeout( ...
-                    siibra.internal.API.featuresPageForParcellation( ...
-                        atlasId, ...
-                        parcellationId, ...
-                        page, ...
-                        size)...
-                );
-                featureList{page} = nextPage.items;
-                processedElements = processedElements + numel(nextPage.items);
-            end
-            featureList = cat(1, featureList{:});
-        end
-        function absoluteLink = parcellationFeature(atlasId, parcellationId, featureId)
-            % get specific feature by feature id.
-            relativeLink = "atlases/" + atlasId + ...
-                            "/parcellations/" + parcellationId + ...
-                            "/features/" + featureId;
-            absoluteLink = siibra.internal.API.absoluteLinkV2(relativeLink);
-        end
-        function absoluteLink = featuresForRegion(atlasId, parcellationId, regionName)
-            relativeLink = "atlases/" +atlasId + ...
-                            "/parcellations/" + parcellationId + ...
-                            "/regions/" + regionName + "/features";
-            absoluteLink = siibra.internal.API.absoluteLinkV2(relativeLink);
+        function features = featuresForRegion(region)
+            relativeLink = "regions/" + region.Name + "/features";
+            absoluteLink = siibra.internal.API.absoluteLinkV3(relativeLink);
+            parameters = "parcellation_id=" + region.Parcellation.Id;
+            features = siibra.internal.API.collectItemsAcrossPages(absoluteLink, parameters);
         end
-        function absoluteLink = regionFeature(atlasId, parcellationId, regionName, featureId)
-            relativeLink = "atlases/" +atlasId + ...
-                            "/parcellations/" + parcellationId + ...
-                            "/regions/" + regionName + ...
-                            "/features/" + featureId;
-            absoluteLink = siibra.internal.API.absoluteLinkV2(relativeLink);
+        function absoluteLink = tabularFeature(region, featureId)
+            relativeLink = "feature/Tabular/" + featureId + ...
+                            "?parcellation_id=" + region.Parcellation.Id + ...
+                            "&region_id=" + region.Name;
+            absoluteLink = siibra.internal.API.absoluteLinkV3(relativeLink);
         end
     end
     
diff --git a/+siibra/+items/+features/ReceptorDensity.m b/+siibra/+items/+features/ReceptorDensity.m
index 1042e8d..7074a23 100644
--- a/+siibra/+items/+features/ReceptorDensity.m
+++ b/+siibra/+items/+features/ReceptorDensity.m
@@ -7,7 +7,6 @@
         Id string
         Description string
         Name string
-        DOI string
         Fingerprint string
         Unit string
     end
@@ -15,19 +14,16 @@
     methods
         function obj = ReceptorDensity(region, receptorJson)
             obj.Region = region;
-            obj.Id = receptorJson.x_id;
-            obj.Description = receptorJson.metadata.description;
-            obj.Name = receptorJson.metadata.fullName;
-            obj.DOI = "https://doi.org/" + receptorJson.urls.doi;
+            obj.Id = receptorJson.id;
+            obj.Description = receptorJson.description;
+            obj.Name = receptorJson.name;
             obj.Unit = "fmol/mg";
         end
         
         function fingerprints = get.Fingerprint(obj)
             fingerprintJson = siibra.internal.API.doWebreadWithLongTimeout( ...
-                siibra.internal.API.regionFeature( ...
-                obj.Region.Parcellation.Atlas.Id, ...
-                obj.Region.Parcellation.Id, ...
-                obj.Region.Name, ...
+                siibra.internal.API.tabularFeature( ...
+                obj.Region, ...
                 obj.Id));
             fingerprintStruct = fingerprintJson.data.fingerprints;
             receptors = fieldnames(fingerprintStruct);
diff --git a/+siibra/+items/Parcellation.m b/+siibra/+items/Parcellation.m
index 2021d73..b0364af 100644
--- a/+siibra/+items/Parcellation.m
+++ b/+siibra/+items/Parcellation.m
@@ -85,6 +85,7 @@
         end
 
         function features = getAllFeatures(obj)
+            error("API v3 has no features on parcellation level!");
             cached_file_name = siibra.internal.cache(obj.Name + ".mat", "parcellation_features");
             if ~isfile(cached_file_name)
                 features = siibra.internal.API.featuresForParcellation(obj.Atlas.Id, obj.Id);
diff --git a/+siibra/+items/Region.m b/+siibra/+items/Region.m
index 287f4f0..56f57af 100644
--- a/+siibra/+items/Region.m
+++ b/+siibra/+items/Region.m
@@ -45,11 +45,7 @@
         function features = getAllFeatures(obj)
             cached_file_name = siibra.internal.cache(obj.NormalizedName + ".mat", "region_features");
             if ~isfile(cached_file_name)
-                features = siibra.internal.API.doWebreadWithLongTimeout( ...
-                    siibra.internal.API.featuresForRegion( ...
-                    obj.Parcellation.Atlas.Id, ...
-                    obj.Parcellation.Id, ...
-                    obj.Name));
+                features = siibra.internal.API.featuresForRegion(obj);
                 
                 % make sure to always return a cell array
                 if ~iscell(features)
@@ -64,7 +60,8 @@
 
         function receptorDensities = getReceptorDensities(obj)
             allFeatures = obj.getAllFeatures();
-            receptorIdx = cellfun(@(e) strcmp(e.x_type,'siibra/features/receptor'), allFeatures);
+            featureTypes = cellfun(@(e) e.x_type, allFeatures, "UniformOutput",false);
+            receptorIdx = strcmp(featureTypes, "siibra-0.4/feature/tabular/receptor_density_fp");
             if ~any(receptorIdx)
                 receptorDensities = siibra.items.features.ReceptorDensity.empty;
                 return