For example, on certain genetic backgrounds, single knockouts of Mer (36), Tim-1 (51), Tim-4 (40), SCARF1 (42), and CD300f (41) all have a common phenotype that include defective apoptotic cell clearance, the subsequent production of auto-antibodies, and SLE-like autoimmunity. The gene discussed is MERTK; the disease is systemic lupus erythematosus.