PKM and cancer: In line with the classical Warburg effect, we observed that TH induces: (i) the switch from the PKM1 isoform (constitutively activated and expressed in terminally differentiated tissues) to the PKM2 isoform (characteristic of all proliferating cells, especially cancer cells) [45,46]; and (ii) up-regulation of the lactate dehydrogenase gene LDHA.