ACPA, anti-cyclic citrullinated peptide antibody; ANA, antinuclear antibody; ANCA, anti-neutrophil cytoplasmic antibody; ARS, aminoacyl-tRNA synthetase; KL-6, Krebs von den Lungen-6; MPO, myeloperoxidase; PR3, proteinase 3; T-SPOT, T-cell spot test for tuberculosis; Ig, immunoglobulin. The gene discussed is BTG3; the disease is tuberculosis.