Meanwhile, target genes related to down-methylated circRNAs were significantly involved in Tryptophan metabolism, RIG-I-Like receptor signaling pathway, Retinol metabolism, MAPK signaling pathway, Linoleic acid metabolism, Herpes simplex infection, GnRH signaling pathway, Cysteine and methionine metabolism, Butanoate metabolism and ABC transporters (Fig. 6b). Here, GNRH1 is linked to herpes simplex infectious disease.