FGD1 and systemic lupus erythematosus: One CpG site that reached suggestive significance for correlation with disease activity in African American lupus patients, cg24682077 (FDR-adjusted P = 5.35 × 10–2), is associated with FYVE, RhoGEF, and PH domain containing 1 gene FGD1. FGD1 interacts with Rho GTPase Cdc42, which regulates neutrophil motility in response to extracellular signals (34).