ProS is only able to bind to Tyro3 and Mertk, Gas6 can bind to all three TAM receptors (Axl > Tyro3 >>> Mertk), whereas, in a specific tumor microenvironment such as the presence of PtdSer, Mertk and Tyro3 are hyperactivated but their affinities for Gas6 are lower than Axl [60, 62, 63]. Here, MERTK is linked to neoplasm.