Cancer cells interact with MSCs, thereby leading to changes in MSCs' phenotype and inducing them to adopt features of CAFs such as the expression ofα-SMA, FSP1 (Fibroblast-Specific Protein), or FAP (Fibroblast-Activated Protein) [157] or, depending on the cancer type, MSCs can further differentiate [114]. The gene discussed is FAP; the disease is cancer.