Angiotensin receptor blockers (ARB) such as losartan have been shown to improve the bioavailability of drugs such as doxorubicin and nanoparticles in xenotransplanted models of pancreatic cancer and melanoma by decreasing the percentage of α-SMA+ cells and the amount of collagen in the tumor stroma, and the tumor size in murine models [186,187]. This evidence concerns the gene ACTA1 and melanoma.