To analyse the proliferation capacity, we cultured tumour cells lines of different organs (HT29 and SW480 colon carcinoma; MCF-7 and MDA MB468 breast cancer; PC3 prostate cancer; T24 bladder carcinoma) at physiological and diabetogenic glucose concentrations without and with the addition of 100 ng ml−1 insulin (see Table 1A). The gene discussed is INS; the disease is breast carcinoma.