For FCN3, the heterozygous CG genotype of rs3813800 was more frequent among SLE patients (36.5%) than HCs (27.0%) (OR, 1.55 [95% CI, 1.02 to 2.38]; P = 0.041), while the CC genotype was significantly less frequent among SLE patients (11.5% vs. 26.0%) (OR, 0.37 [95% CI, 0.22 to 0.63]; P < 0.001). Here, FCN3 is linked to systemic lupus erythematosus.