WNK2 and cancer: Aberrantly activated mitogen-activated protein kinase (MAPK) signaling exists in over 85% of the cancers and accounts for more than 40% of cancer cases.1 MAPK pathway inhibitors are under laboratory and clinical investigation to identify their efficacy against various tumors,2 but MAPK signal reactivation could invariably develop and lead to treatment failure.3 Interestingly, cancer cells that acquire drug resistance are used to an optimal level of MAPK signaling,4 and enhancing MAPK activity in these cells has antitumor effects.