A deep understanding of the biology and functions of type I, II, and NKT-like cells as well as their interplay with cell types acting in innate (neuthrophils, innate lymphoid cells, machrophages, and dendritic cells) and adaptive immunity (CD4+,CD8+, and double negative T cells) should be important to design potential immunotherapies for infectious and autoimmune diseases. Here, CD4 is linked to autoimmune disease.