We hypothesized that there might be an association between the presence of Vitamin K epoxide reductase complex 1 (<i>VKORC1</i>) and/or cytochrome P450 <i>2C9 (CYP2C9)</i> variant alleles and the early onset of IPF in the members of this family. The gene discussed is CYP2C9; the disease is idiopathic pulmonary fibrosis.