Pyruvate kinase muscles (PKMs) have two splicing isoforms, the PKM1 and PKM2. In cancer cells, especially colon cancer cells, the amount of PKM2 increases due to the regulation of splicing by PTB1, and PMK1 increases when PTB1 expression is suppressed by miR-124. The gene discussed is PTBP1; the disease is malignant colon neoplasm.