In particular, we found that the CTS family members, including CTSA, CTSB, CTSC, CTSD, CTSG, CTSH, CTSK, CTSS, and CTSZ, were gradually upregulated during the progression of PQ‐induced ALI, among which CTSK exhibited the most significant accumulation (Figure1A; Figure S1A–I, Supporting Information). Here, CTSD is linked to acute respiratory distress syndrome.