MMP21 and cancer: Therefore, we compared gene expression for cancer-associated fibroblast (CAF) markers including MMP2 [30], MMP9 [31], MMP21 [32], TGFA [33], CXCL12 [34], ITGA3 [35], FAPα [34], and IL32 [36] in fibroblasts derived from normal skin and MF tumors.