TGFB1 and idiopathic pulmonary fibrosis: After TGF-β1 treatment, PRRX1a and PRRX1b levels were decreased at the mRNA level only in control lung fibroblasts at 24 hr but at both mRNA and protein levels in control and IPF lung fibroblast only at 48 hr (see Figure 3A and Figure 3—figure supplement 1).