TNF and type 1 diabetes mellitus: A study on the Tunisian population investigating the association between TNFA promotor polymorphisms and type 1 diabetes showed that the haplotypes containing the TNFA −857C and TNFA −238G are the most likely haplotypes associated to the development of this disease [61] which is consistent with our result showing the association between GCG haplotype and global schizophrenia.