NOS2 and combined immunodeficiency: Liao et al. have found that isoliquiritigenin inhibited the activation of NF-κB and reduced the expressions of prostaglandin-endoperoxide synthase 2 (PTGS2), TNF-α, and nitric oxide synthase 2 (NOS2) in the colon tissues of 5-FU-induced CID mice, as well as repaired the integrity of intestinal mucosal barrier through restoring the height of intestinal villi and alleviating edema in intestinal epithelium (Liao et al., 2022).