RBX1 and neoplasm: Subsequently, our in vivo orthotopic bladder cancer cell xenograft model in nude mice also showed that overexpression of ROC1 resulted in a significant acceleration of tumor cell xenograft growth (Fig. 1e, f), while our western blot analysis of the tumor cell xenografts confirmed ROC1 upregulation in the pROC1 group of mice compared with the vector-control group of mice (Fig. 1g).