To ensure a high ratio of PKM2/PKM1 in cancer cells, three heterogeneous nuclear ribonucleoproteins (hnRNPs) proteins, including polypyrimidine tract-binding protein (PTB, also known as hnRNPI), hnRNPA1, and hnRNPA2, alternatively splice transcripts of the PKM gene and facilitate the generation of PKM2 [7]. The gene discussed is PTBP1; the disease is cancer.