GCG and hypertrophic cardiomyopathy: KEGG pathway enrichment analysis of these upregulated DE circRNAs revealed that host genes were mainly involved in glycogen metabolism-related signaling pathways (e.g., insulin signaling pathway, starch and sucrose metabolism and glucagon signaling pathway), muscular function maintenance and development-related signaling pathways (e.g., hypertrophic cardiomyopathy (HCM), TGF-beta signaling pathway, and AMPK signaling pathway) (Figure 4D).