Single nucleotide polymorphism analysis indicates the following variants are associated with T1D and B-cell receptor (BCR) and B-cell differentiation: PTPN22, PTPN2, Src homology 2B3 adapter gene (SH2B3), and immunoregulatory cytokines IL-10, IL-19, and IL-20 [88, 89]. The gene discussed is PTPN2; the disease is type 1 diabetes mellitus.