STAT3 and cancer: Numerous pieces of evidence have identified the aberrant activation of STAT3 as a critical driver of various aspects of malignant progression in bladder cancer, including cell proliferation [28], epithelial-to-mesenchymal transition [29,30], angiogenesis [31], cancer metabolic reprogramming [32,33], cancer stemness maintenance [34,35], and evasion of immunosurveillance [36,37].