adjacent to subepithelial intestinal fibroblast crypt-top fibroblast 2024-09-23T11:14:04Z S2b fibroblast A subepithelial intestinal fibroblast that is located adjacent to the top of the crypt of Lieberkuhn. Characterized by high experession of PDGFRα, this cell secretes a range of signaling factors, including WNTs and BMPs, that drive epithelial differentiation, creating a gradient that regulates the balance between stem cell maintenance and differentiation. S2b fibroblasts are located at the top of the crypt and express NRG1 and NPY. CTFs top pericryptic fibroblast wall of crypt of Lieberkuhn