FCGR2A and sarcoidosis: Moreover, since an aberrated number of copies (CN ≠ 2) of FCGR genes would lead to disruption in the presence of FcγRs on immune cells, causing up- or down-regulation of an (auto)immune response, in the current study we performed the first in the world analysis of copy number variation (CNV) of FCGR2A, FCGR2B, FCGR2C, FCGR3A and FCGR3B genes in an ethnically homogenous, Caucasian group of patients with sarcoidosis and healthy controls.