HLA-DRB1 and type 1 diabetes mellitus: In a recent study in North West Ethiopia, GAD-negative diabetes patients had the HLA-DRB1*04, including the HLA-DRB1*15 alleles (61), and the HLA-DRB1*15 allele, which has also been shown in other populations to confer one of the strongest protection for type 1 diabetes (121).