The best-studied infection-derived antigens are membrane lipids from mycobacteria; these include dideoxymycobactin82, glucose monomycolate83, mannosyl-1B-phosphomycoketide84, and phosphatidylinositol mannoside-485 and are recognized by CD1a, CD1b, CD1c, and CD1d, respectively. The gene discussed is CD1A; the disease is infection.