RYK and neoplasm: Through a siRNA library screening that targeted most genes encoding RTKs and subsequent validation, we found that knockdown of 4 RTK receptors (FGFR2, RON, EPHA1, and RYK) via siRNA sensitized MET-addicted tumor cells to PF, while b-FGF-induced activation of FGFR2 conferred resistance to the PF.