EPHB4 and urinary bladder cancer: Several receptor tyrosine kinases (RTKs), such as fibroblast growth factor receptor (FGFR) 1 and 3 [8], human epidermal growth factor receptor 2 (HER2) [9], insulin-like growth factor-1 receptor (IGF1R) [9], and ephrin type-B receptor 4 (EphB4) [9], have been reported to be involved in the invasion of bladder cancer.