Abstract: The present invention relates to mutant kinase polypeptides and kinase variants selected from the group consisting of AATYK (AATK), ABL1, ACK1, ALK, ARG, AXL, BMX, BRK, BTK, CCK4, CSFR1, CSK, DDR1, DDR2, EGFR, EPHA1, EPHA2, EPHA3, EPHA4, EPHA5, EPHA6, EPHA7, EPHA10, EPHB1, EPHB2, EPHB3, EPHB4, EPHB6, FAK, FER, FES, FGFR1, FGFR2, FGFR4, FLT3, FRK, FYN, HER2, HER3, HER4, IGF1R, INSR, ITK, JAK1, JAK2, JAK3, LCK, LMTK2 (AATYK2/BREK), LYN, MATK, MER, MET, NTRK1, NTRK2, NTRK3, PDGRFA, PDGFRB, PTK-9, PYK2, RET, RON, ROR1, ROR2, ROS, RYK, STYK, SYK, TEC, TEK, TIE, TNK1, TXK, TYK2, TYRO3, VEGFR1, VEGFR2, VEGFR3, YES1, and ZAP70, nucleotide sequences encoding the mutant kinase polypeptides and kinase variants, as well as various products and methods useful for the diagnosis and treatment of various kinase-related diseases and conditions, including the screening for and identification of novel protein kinase modulators.