Conversely, prostaglandin E2 (PGE2, 100 nM) treatment which decreases myofibroblastic differentiation (Fernandez and Eickelberg, 2012) was associated with an increase of PRRX1 isoforms mRNA and protein in both control and IPF fibroblasts (Figure 3A and Figure 3—figure supplement 1) at 48 hr. This evidence concerns the gene PRRX1 and idiopathic pulmonary fibrosis.