PKM and cancer: Overexpression of PKM2 is a trait shared by the majority of cancers and this PK isoform is critical for cancer metabolic reprograming via its functions as a pyruvate kinase in the cytosol and a protein kinase and transcriptional coactivator in the nucleus.40 Our data revealed an unexpected role of nuclear PKM2 in promoting HR-mediated repair of DNA damage, positioning PKM2 at the convergence of metabolic reprograming and DNA repair (Fig. 7).