HLA-DRB1 and interstitial lung disease: For example, high titers of rheumatoid factor [RF] and anti-cyclic citrullinated peptide [CCP] antibodies are specifically associated with the development of ILD in patients with RA (Inui et al., 2008; Giles et al., 2014; Kelly et al., 2014; Akiyama and Kaneko, 2022), in which the HLA-DRB1*15 allele may confer a specific susceptibility to the production of anti-citrullinated fibrinogen antibodies (Gyetvai et al., 2010).