Similarly, in vitro treatment of AECs isolated from IPF lungs with CSP7 markedly reduced p53 expression and activation of caspase-3, while uninjured AECs isolated from non-IPF lung tissue failed to respond to CSP7, suggesting that CSP7 specifically targets injured AECs with dysregulated p53 expression. Here, CASP3 is linked to idiopathic pulmonary fibrosis.