A low level of IL-6 in carriers with G allele, on the one hand, may exert antitumorigenic effects predominately in a diabetic state, resulting in that diabetic women with CG/GG genotypes had a marginally decreased risk of breast cancer compared to women with CC genotype in our study [OR (95%CI): 0.36 (0.12, 1.07)]. The gene discussed is IL6; the disease is breast cancer.