The IHC assay was also used to detect the expression of Nrf2, the critical factor of the Keap1/Nrf2/HO-1 pathway, in the liver tissues of ALI model mice, and the results showed that FPHLP enhanced the expression of Nrf2 in mice with CCl4-induced ALI (Figure 4G). This evidence concerns the gene KEAP1 and acute respiratory distress syndrome.