Advances in multi-omics research have elucidated the molecular mechanisms underlying the pathogenesis and progression of bladder cancer, including driver gene mutations (e.g., FGFR3, TP53/RB1), dysregulation of signaling pathways (such as PI3K/AKT/mTOR and RAS-MAPK), epigenetic alterations, non-coding RNA networks, tumor microenvironment remodeling, and metabolic reprogramming. This evidence concerns the gene PIK3CA and urinary bladder cancer.