In macrophages, after Toll like receptor 4 (TLR4) stimulation, HIF1α and the “inactive” form of PKM2 interact to induce a metabolic switch, yielding a completely different effect than that observed in prostate cancer cells, as macrophages acquire a Warburg-like phenotype necessary for their complete activation (Palsson-McDermott et al., 2015). Here, PKM is linked to prostate carcinoma.