We identified down-regulation of CAB39L, the allosteric activator of LKB1 in IPF alveolar septae, and found that levels of CAB39L were significantly inversely correlated with SNAI2 (Snail2) suggesting that reduction of CAB39L in IPF alveolar epithelium leads to LKB1 inactivation and promotes EMT. This evidence concerns the gene STK11 and idiopathic pulmonary fibrosis.