In these diseases, TLR9 is activated by various DAMPs, including cell-free DNA in obesity and mtDNA and HMGB1 released from the damaged liver in NASH (Montes et al., 2015; Nishimoto et al., 2016; Saito et al., 2019). This evidence concerns the gene TLR9 and obesity due to melanocortin 4 receptor deficiency.