Beyond RA, the HLA-DRB1 alleles strongly influence the risk of developing sarcoidosis subtypes including Löfgren’s syndrome (acute clinical presentation of systemic sarcoid) [11–13]; in addition, there have been consistent associations of DR4 with idiopathic bronchiectasis as well as obliterative bronchiolitis [14, 15]. This evidence concerns the gene TNFRSF10A and rheumatoid arthritis.