In the subgroup treated with insulin (n = 160), patients showed a significantly lower incidence of pTNM stage I tumors (15.0% vs. 30.5%; p < 0.001) and a markedly higher rate of ductal carcinoma in situ (DCIS) (10.0% vs. 2.3%; p < 0.001). The gene discussed is INS; the disease is ductal breast carcinoma in situ.