Submucosal S3 fibroblasts occupy deeper layers and crypt base regions and are enriched for GREM1, C7, OLFM4, PTGS2, THY1, SEMA3A and GLI1, consistent with crypt-support or trophocyte roles. Cluster-level annotations describe RSPO3, GREM1, DCN and C3 as strong markers of submucosal fibroblasts (for example Stroma_2_0) and we note that S3 populations have lower dataset diversity and appear deeper than lamina propria fibroblasts, especially in resection-derived data. Multiple clusters labeled as Fibroblasts Submucosal (aka Crypt Support/Trophocytes/S3) recur with similar signatures, supporting a distinct S3 fibroblast class even though a dedicated CL term is still needed.
Inherited from Prelim annotation
Set of Labels Description
Cell annotations (Prelim annotation) are based on the finest possible label that could be used to describe each of the ~500 clusters found during integration and subclustering