As many as 200 endogenous retroviral sequences have been reported, some of which (HRES-1, HERV-E 4-1, HERV-K10, HERV-K18 HERVs) are related to the development of SLE through: (1) autoantibody production by molecular mimicry, (2) stimulation of intracellular sensor molecules by viral nucleic acids, and (3) epigenetic regulation of host genes (52, 53). The gene discussed is RAB4A; the disease is systemic lupus erythematosus.