CLDN1 and idiopathic pulmonary fibrosis: Emerging evidence suggests that the EMT process and fibroblast activation are major events in IPF pathogenesis.17, 18, 19 In the present study, a second infusion of apoptotic cells with simvastatin further enhanced the mRNA abundance of several epithelial markers, such as E-cadherin and claudin-1, and reduced expression of α-smooth muscle actin (SMA), a marker of myofibroblast differentiation, in primary alveolar type II epithelial (AT II) cells on day 14 post-bleomycin treatment, compared to the BLM+Apo (single or twice) or BLM+single Apo+Simv (Figures 6a–c) groups.