RHOA and systemic lupus erythematosus: GEF–H1 exemplifies functional pleiotropy in immune dysregulation: In systemic lupus erythematosus (SLE), PPP2R2A‐mediated dephosphorylation of GEF–H1 activates the RhoA–ROCK axis, driving pathogenic IL‐17/IFN‐γ production in T cells [26] (Table 2).