FcγRIIA is ubiquitously expressed on human myeloid cells, and high-affinity FcRIIA alleles correlate with an increase in effectiveness of the ADCP-inducing drug rituximab and lupus susceptibility (Bruhns and Jönsson, 2015; Nimmerjahn and Ravetch, 2006). Here, FCGR2A is linked to systemic lupus erythematosus.