CYP1A1 and Insulin resistance: Xia et al. (2019) identified AhR/CYP1A1 and AhR/TNF-α signaling pathways as contributors to insulin resistance and hepatic lipid accumulation. AhR’s impact on downstream genes is primarily mediated by its binding to xenobiotic response elements (XRE) within the promoter regions of target genes, which subsequently regulates gene expression (Sato et al., 2008). There are three XRE fragments in the FGF21 promoter region (Girer et al., 2019), suggesting that the AhR-DNA complex may regulate FGF21 expression, thereby influencing the expression of downstream lipid metabolism-related factors.