Expression of the receptors HER3 and HER4, and ligands HRG1α, HRG1β, HRG2α, HRG2β, HRG3 and HRG4 was detected in 99, 63, 90, 61, 63, 43, 75 and 91% of the bladder cancer cases, respectively. The gene discussed is NRG3; the disease is urinary bladder cancer.