FCGR2A and systemic lupus erythematosus: The higher affinity HNA‐1a has been associated with an increased risk of a condition marked by FcγR‐mediated neutrophil activation, known as anti‐neutrophil cytoplasmic antibody systemic vasculitis,168 whereas the lower affinity HNA‐1b isoform has been linked to SLE development.169, 170