Importantly, these results are supported by the expression of tissue-specific HTRs, such as HTR1B, HTR2A, HTR2B and HTR7, in the liver (Li et al., 2018), the relationship of HTR2A with hepatic steatosis (Li et al., 2018; Choi et al., 2018; Wang et al., 2020) and that of HTR2B with hepatocyte proliferation (Ruddell et al., 2008; Wouters et al., 2007). Here, HTR2B is linked to fatty liver disease.