PKM and cancer: Warburg effect is a hallmark of cancer which is characterized by increased glucose uptake and lactate production (DeBerardinis et al., 2008) where the PKM gene regulates the key step of glycolysis, and thus the splicing switch from PKM1 to cancer-specific PKM2 isoforms plays a key role in the Warburg effect (Christofk et al., 2008; Dayton et al., 2016).