ACTA1 and idiopathic pulmonary fibrosis: In IPF fibroblasts subjected to UCP2 silencing, we observed an increase in cell proliferation with a concomitant induction of cyclin D1 and phosphorylated Rb, while the expression of myofibroblast differentiation markers, α‐smooth muscle actin (α‐SMA) and collagen 1a1 (COL1a1) was reduced (Figure 5a–f).