CYBB and systemic lupus erythematosus: This study provides insight into the functional immune roles for the uncharacterized and unsilenced CXorf21 protein and, moreover, is an integral piece into understanding the role this gene, in collaboration with other SLE putative risk genes, SLC14A4, X-linked TLR7, and potentially NCF1 (NOX2 subunit) contribute to the X-chromosome dose effect that explains the female bias in SLE and pSS.