NOD2 and pulmonary sarcoidosis: Various single nucleotide polymorphisms (SNPs) are associated with fibrotic pulmonary sarcoidosis; these include SNPS for: (a) GREM 1, which encodes for gremlin, a secreted glycoprotein and member of the bone morphogenic proteins [73]; (b) Card15 (caspase recruitment domain-containing protein 15, also known as NOD2 [74], and (c) isoform 3 of transforming growth factor beta (TGF-β3) [75].