TLR7 is expressed on a variety of immune cells, and decreased macrophage, CD4-CD8- thymocyte, and peripheral CD4+ T cell populations were observed [42]; therefore, B cell-specific TLR-deficient NOD studies are needed to elucidate the direct impact of TLR signaling in B cells on T1D pathogenesis. This evidence concerns the gene CD8A and type 1 diabetes mellitus.