CD226 and type 1 diabetes mellitus: However, due to the lack of knowledge about the contribution of some rare genetic risk variants of T1DM, such as SH2B3, CD226, and CTLA4, prognostic models involve only the gene variants, whose changes are highly reliably associated with the mechanisms of development of islet autoimmunity and accompanied with the dysregulation of antigen-presenting cells, activation of T cell signaling, and regulation of T1 interferon levels and cytokine signaling [16].