expresses expresses stromal cell fibrocyte of adventitia of ureter FMA:261289 A stromal cell that is part of the outer adventitial layer of the ureter. This cell type is marked by expression of periostin (POSTN) in mice, and it is derived from Foxd1+ mesenchymal progenitors around embryonic day 12.5. The adventitial fibrocyte initiates differentiation earlier than smooth muscle cells and becomes terminally differentiated by E16.5-18.5 in mice, exhibiting low proliferative capacity in adulthood. ureter adventitial cell periostin