Thus, to validate increased expression of SIX1 in IPF, we quantified the expression of SIX1, EYA1, and EYA2 mRNA by quantitative PCR (qPCR) in IPF (n = 24), COPD (n = 18), and controls (n = 12). This evidence concerns the gene SIX1 and idiopathic pulmonary fibrosis.