PARP1 and cancer: Moreover, emerging evidence suggests that switching the PKM isoform to PKM1 markedly hinders tumor progression in various cancers.[15, 18, 44] Here, we identified PKM1 as a direct substrate of NUDT13 and PARP1, and that PKM1 is responsible for the OXPHOS phenotype and tumor‐suppressive effect induced by NUDT13.