TGFB1 and melanoma: For example, exosomes secreted by bladder cancer cells activate and drive differentiation of healthy fibroblasts to CAFs through the TGFβ-mediated SMAD pathway 29, and melanoma-derived exosomal miR-125b-5p targets lysosomal acid lipase A (LIPA) in macrophages and promotes phenotypic changes in macrophages 10.