APOA4 and colitis: Its production ApoA-4-containing lipoprotein was secreted by the small intestine in response to fat absorption, and was considered as an endogenous anti-inflammatory protein that could inhibit DSS-induced inflammation and colitis (Vowinkel et al., 2004), and could promote cholesterol efflux from cultured fibroblasts and adipose cells in vitro (Ordovas and Schaefer, 2000).