PKM and urinary bladder cancer: The multifaceted function of hnRNP-A1 in regulating the alternative splicing of numerous gene variants underscores its significance in bladder cancer—for instance, hnRNP-A1 mediates the c-Myc-enhanced pyruvate kinase (PK)M2/PKM1 isoform switch by selectively including exon 10 and excluding exon 9 during the alternative splicing of PKM pre-mRNA (31).