Although Saa3 deficiency in male Ldlr-/- mice reduced aortic and aortic sinus atherosclerosis and increased Trem2 transcript levels in bone marrow-derived macrophages (BMDMs), Saa3-/- knockout in female Ldlr-/- mice increased aortic atherosclerosis and decreased Trem2 expression in BMDMs. The gene discussed is TREM2; the disease is sinusitis.