EPHA2 and melanoma: In addition, EPHA2 possesses ligand-independent kinase activity in many cultured tumor cell types [8,10] and overexpression of EPHA2 serves both as a prognostic marker and therapeutic target in various human epithelial cancers (e.g., breast, gastric, and lung), glioblastoma, and melanoma, whereas EPHA2 sequence variants have been associated with susceptibility to Kaposi’s sarcoma [9,11,12].