NOD2 and sarcoidosis: Several other non-HLA genes have been associated with sarcoidosis, such as prostaglandin G/H synthase/cyclooxygenase (PTGS2/COX2), neurogenic locus notch homolog 4 (NOTCH4), nucleotide-binding oligomerization domain-containing protein 2 (NOD2), and Butyrophilin-like 2 (BTNL2) [11,12,13,14,15].