ERBB2 and prostate cancer: In conclusion, the three main findings of the present study are: 1) that the association of ErbB2-IR with the Gleason score seen at diagnosis is most likely due to the association of both parameters with the rate of tumour cell proliferation; 2) that although ErbB2 expression at the mRNA level is sensitive to the concentration of circulating androgens, there is no association between ErbB2-IR and AR-IR in prostate cancer.