Therefore in our current study aiming to minimize the insufficient protection against biased results, we used our multi-center cohort of patients with T1D in the Chinese Han population and multivariate analysis to investigate the genetic association of non-HLA genes by genotyping 55 single nucleotide polymorphisms (SNPs) in VTCN1, PTPN22, CTLA4, SUMO4, CD274, IL2RA, INS, DHCR7, ERBB3, VDR, CYP27B1, CD69, CD276, PTPN2, UBASH3A and IL2RB genes. The gene discussed is CYP27B1; the disease is type 1 diabetes mellitus.