A study showed that Ac-SDKP suppressed ACE–Ang II–Ang II type 1 receptor (AT1) axis and activated ACE2-angiotensin-(1-7) [Ang-(1-7)]-Mas axis in silicotic C57BL/6 mice and Ang II-stimulated mouse lung type II epithelial cells MLE-12 to reduce EMT and alleviate lung fibrosis [111]. Here, ACE is linked to pulmonary fibrosis.