Furthermore, we demonstrated that HNF1B exerts its tumor-suppressive roles by concurrently inhibiting the mitogen-activated protein kinase (MAPK) signaling pathway and the epithelial-mesenchymal transition (EMT) process.<h4>Conclusion</h4>Our study unveils a novel epigenetic mechanism in bladder cancer, whereby promoter hypermethylation silences HNF1B, thereby promoting tumor progression through activation of the MAPK pathway. The gene discussed is HNF1B; the disease is neoplasm.