TDO2 and idiopathic pulmonary fibrosis: Reanalysis of single-cell sequencing data confirmed TDO2 expression in IPF patient myofibroblasts (Figure 6A); however, we did not detect appreciable expression of IDO1 in human myofibroblasts, and overall expression of IDO1 was shown to decrease in the lungs of fibrotic mice while expression of TDO2 increased (Figure 7, A and B).