Background:We previously demonstrated that AIB1 overexpression is an independent molecular marker for shortened survival of bladder cancer (BC) patients.In this study,we characterised the role and molecular mechanisms of AIB1 in BC tumorigenicity.Methods:AIB1 expression was measured by immunohistochemistry in non-muscle-invasive BC tissue and adjacent normal bladder tissue.In addition,the tumorigenicity of AIB1 was assessed with in vitro and in vivo functional assays.