Confocal immunofluorescence microscopy demonstrated increased expression of DRP1 and MFF in α-SMA–positive myofibroblasts and fibroblasts within the fibroblastic foci in human IPF lungs, but not in normal alveolar fibroblasts in the control lungs (Figure 5, E and F, and Supplemental Figure 9, E–H). Here, ACTA1 is linked to idiopathic pulmonary fibrosis.