CD4 and systemic lupus erythematosus: For example, iKIR expression by CD4+ T cells is increased in ankylosing spondylitis (1–6% of all CD4+ cells are KIR3DL2+, rising to 10–60% of Th17 CD4+ cells [9]) and other autoimmune diseases such as lupus show similar increases in iKIR expression [43].