THY1 and melanoma: In melanoma, CAFs express high levels of alpha-smooth muscle actin (a-SMA), one of the most important activation and differentiation markers, as well as other conventional fibroblast-activating markers such as fibroblast-activating protein (FAP), fibroblast-specific protein 1 (FSP1), osteonectin, desmin, platelet-derived growth factor receptor (PDGFR), POSTN, CD90, and vimentin [98].