PTPRC and neoplasm: In WD-SCCs, Sdf1 was expressed by fibroblasts (Fig. 1b) and immunodetected in stromal cells (Fig. 1c), as previously described [32, 35], whereas tumor cells and CD45+ immune cells (deficient in T-cell in nude immunodeficient mice) exhibited a faint or undetectable Sdf1 expression (Fig. 1b).