MAPT and idiopathic pulmonary fibrosis: The IPF susceptibility signals at DSP, FAM13A, 7q22.1(ZKSCAN1), and 17q21.31 (MAPT) have also beenreported as associated with COPD, although with opposite effects (i.e., the alleleassociated with increased risk of IPF being associated with decreased risk of COPD).Spirometric diagnosis of COPD was based on a reduced FEV1/FVC ratio.