Then, by using an in vitro CEP55 knockdown system performed by targeted siRNA and an in vivo subcutaneous tumorigenesis model in nude mice, we observed that the knockdown of CEP55 markedly restrained the proliferation of gallbladder cancer via impeding AKT and ERK pathway activation, resulting inG2/M phase arrest, DNA damage, and apoptosis. This evidence concerns the gene CEP55 and gallbladder cancer.