Introduction Systemic Lupus Erythematosus (SLE) is an autoimmune disease. The exact cause is still unknown, and the severity can vary person-to-person. Because the cause is still unknown, treatment is still difficult. Research is ongoing to develop better treatment options. What is SLE? SLE is an autoimmune disease that affects multiple organ systems. While the exact cause is still unknown, scientists believe it is related to genetic, hormonal, and environmental factors. In particular, the genes HLA-DR2 and HLA-DR3 are commonly present in people with SLE. Certain proteins, like C1q, C2, and C4 are also deficient in 10% of people with SLE.