EGFR and urinary bladder carcinoma: Notably, expression of the epidermal growth factor receptor (EGFR, also known as ErbB1) is upregulated in approximately 74% of bladder carcinoma tissues compared to that in normal urothelial tissues.[4] However, several clinical trials have shown that inhibiting of the EGFR has no benefit in BCa patients.[5] These results indicate that inhibition of the EGFR in BCa may not be sufficient, or that the EGFR binds to other receptor tyrosine kinases (RTKs) to form heterodimers.