Further investigation into the factors involved in hepatic cDC1 activation to express IL-15 and IL-15Rα in the liver environments of APAP-ALI mice revealed that although APAP alone or APAP-induced hepatocyte damage did not induce the expression of IL-15Rα in DC1s, treatment with LPS significantly upregulated IL-15Rα expression in DC1s (Supplementary Fig. 12b). Here, MPPE1 is linked to acute respiratory distress syndrome.