Some of the gene-gene interactions may be more subtle than just pair-wise interactions, e.g. in predisposition to T2DM, there are pair-wise interactions between APOB(Thr7Ile) and CETP(Ile 405Val), but also between APOB(Thr7Ile) and GNB(C825T), so CETP and GNB3 polymorphisms may influence each-other via the APOB polymorphism or, alternatively, the effect of the APOB polymorphisms may be influenced by variations in both CETP and the GNB3. This evidence concerns the gene APOB and type 2 diabetes mellitus.