NCF4 and sarcoidosis: In this study, we attempted to determine whether normal nonsynonymous genetic variations identified by the Genbank SNP database or previously described in the literature to be present in the normal population in the genes for p47phox (NCF1), p67phox (NCF2), p40phox (NCF4), gp91phox (CYBB), p22phox (CYBA), DUOX1, DUOX2, TLR2, TLR9 and alpha-1 anti-trypsin (AAT) are associated with an increased susceptibility to tuberculosis, sarcoidosis, recurrent pneumonia, and atypical mycobacterial infection.