While IPF fibroblasts cultured in vitro have been reported to demonstrate senescent characteristics (26), we sought to determine the expression pattern of CDKN2A (encoding both p16INK4a and p19ARF) in our previous scRNA-Seq of IPF lung fibroblasts in vivo (22) (Figure 6A and Supplemental Figure 7A). Here, CDKN2A is linked to idiopathic pulmonary fibrosis.