In this context, it is of interest to note that autoantibodies to heat shock protein 70 [15] and periplakin [23], which have been identified in serum and bronchoalveolar lavage of patients with IPF, have been reported to be associated with a more severe disease, further supporting the presence of an autoimmune response in the pathogenesis of IPF. The gene discussed is PPL; the disease is idiopathic pulmonary fibrosis.