In bladder cancer, HNRNPL promotes the circFAM13B biogenesis through pre-mRNA back-splicing, which competitively binds to the KH3-4 domains of IGF2BP1 and subsequently decreases the binding of IGF2BP1 to the PKM2 3′UTR; thereby weakening PKM2 mRNA stability and reversing glycolysis-induced acidic tumor microenvironment [159]. The gene discussed is PKM; the disease is urinary bladder cancer.