PTPN11 and cancer: SHP2 and SOS1 are common proximal RTK signaling intermediates; the development of potent, specific inhibitors for both SHP2 (SHP099 [131,132]; RMC-4550 [133]) and SOS1 (BAY-293 [134]; BI-3406 [135,136]) has led to new approaches to treating RAS-mutated cancers.