To test whether lymphocyte subtypes are causally associated with T2D risk, we further carried out MR analysis between T2D and absolute count of lymphocyte subpopulations, comprising HLA DR+ NK cells, NKT cells, CD4 Tregs, CD4+ CD8dim T cells, CD8+ T cells, and B cells. The gene discussed is CD8A; the disease is type 2 diabetes mellitus.