PTCH1 and skin basal cell carcinoma: The authors also report that the genotype of PTCH1+ fibroblasts from tumor-free skin of NBCCS patients was similar to that of BCC associated fibroblasts to the extent that NBCCS fibroblasts overexpressed mRNAs encoding MMP-1, MMP-3, and tenascin C, proproliferative factors such as fibroblast growth factor 7 (FGF-7) and stromal cell-derived factor 1 alpha.