HLA-DRB1 and type 1 diabetes mellitus: Moreover, HLA-DRB1 alleles polymorphism have been reported to be associated with other cancers and autoimmune diseases, including cervical squamous cell carcinoma, rheumatoid arthritis, systemic lupus erythematosus, autoimmune hepatitis, inflammatory bowel disease, multiple sclerosis and type 1 diabetes, and meta-analyses have been done for these diseases [25-31].