Most hormone-induced sex-specific immune responses have been studied in animal models and in relation to non-infectious diseases, such as autoimmunity (rheumatoid arthritis, lupus, extrinsic allergic encephalitis/multiple sclerosis), estrogen receptor-α+ breast cancer or infections, such as lymphocytic choriomeningitis virus. The gene discussed is ESR1; the disease is systemic lupus erythematosus.