In response to the IPF-BALF treatment, the MRC-5 fibroblasts increased the expression of vimentin and alpha smooth muscle actin (α-SMA), both markers of fibroblast activation; their expression levels in the cell lysates were normalised to the expression of COX IV, which was used as a housekeeping control protein (Figure 2B). Here, COX4I1 is linked to idiopathic pulmonary fibrosis.