HCAR2 and autoimmune hepatitis: Principal receptors implicated in the associated signaling pathways in the intestine consist of Toll-like receptor 4 (TLR4) (Guo et al., 2015) and G protein-coupled receptors (GPR41/GPR43, GPR109a) (Thangaraju et al., 2009; Kim et al., 2013; Zhao et al., 2018) (Figure 1), while in the liver, NLRs (Luan et al., 2018), TLRs (TLR4, TLR9) (Zhang et al., 2018; Liu et al., 2021a), Ah R (Manfredo Vieira et al., 2018) and GPBAR1 (Biagioli et al., 2019) take part in the progression of AIH (Figure 2).