FCGR2B and systemic lupus erythematosus: Two other SNPs of the FCGR2B (and FCGR2C) promoter define the FCGR2B-2B.4 haplotype [–386C, rs143796418, and –120A, rs780467580, in almost complete linkage disequilibrium (LD)], which associates with increased transcription and SLE (26–29).