PKM and urinary bladder carcinoma: For example, down-regulation of PKM2 by shikonin, an inhibitor of PKM2, re-sensitized the drug resistant bladder cancer cells to cisplatin (Wang et al., 2018); PKM2 expressions were positively associated with gefitinib resistance in colorectal cancer cells, and PKM2 knockdown increased gefitinib efficacy (Li et al., 2015).