a, qRT-PCR of female-biased immune genes in whole skin of healthy humans (n=5 each sex). b, immunohistochemistry images of female-biased immune genes in skin of healthy humans. Scale bar, 50 μm. c, qRT-PCR of female-biased immune genes in monocytes of healthy humans (n=9 each sex). d, qRT-PCR of female-biased immune genes in B cells of healthy humans (n=9 female, 8 male). e, qRT-PCR of female-biased immune genes in skin of SLE patients (SLE) and healthy subjects (N) (n=5 each). f, qRT-PCR of female-biased immune genes in monocytes of SLE patients (SLE) and healthy subjects (N) (n=3 each). g, gene expression by RNA-Seq in primary human keratinocytes with or without estradiol treatment (n=3 independent experiments). h, gene expression by RNA-Seq in primary human keratinocytes with or without testosterone treatment (n=3 independent experiments). i, scatter plot of BAFF expression from RNA-Seq of human skin biopsies versus age at biopsy. Female, F. Male, M. Mean ± s.e.m, * P<0.05, Student’s t-test.