The enrichment analysis result of KEGG pathway show that the target mRNAs of downregulated circRNAs (hsa_circ_0005232, hsa_circ_0000994, hsa_circ_0000690, hsa_circ_0058092, and hsa_circ_0004496) were most significantly enriched in Toll-like receptor signaling pathway, transcriptional misregulation in cancer, Kaposi's sarcoma-associated herpesvirus infection, chemokine signaling pathway, autoimmune thyroid disease, bacterial invasion of epithelial cells, thyroid hormone synthesis, alcoholism, thyroid hormone signaling pathway, and EGFR tyrosine kinase inhibitor resistance (Fig. 6D). The gene discussed is EGFR; the disease is alcohol drinking.