CD4 and autoimmune disease: For example, a study analyzing 21 autoimmune diseases found that approximately 60% of putative causal variants colocalize with super-enhancers marked by H3 lysine 27 acetylation (H3K27ac) in CD4+ T cell populations and B lymphoblastoid cells, including stimulus-responsive enhancers that produce enhancer RNAs (eRNAs) (32).