Significantly upregulated lipid biomarkers during viral infection include betaine-like lipids BLL (22:6/22:6) [14], viral sphingolipid vGSLs [37], host TG (57:8), TG (53:3), TG (64:17), FA (20:4) [15], etc. Significantly downregulated lipid biomarkers include sialic acid GSLs (sGSLs) [14], Cer (38:1; 2), Cer 40:2; 2_isomer1 [15], etc. In addition, host or virus-specific mRNA can also act as biomarkers, such as the host cytochrome oxidase C subunit 1 (COI) gene [9], the thylakoid membrane protein-coding gene psbA [38], and the viral capsid protein-coding gene MCP [38]. This evidence concerns the gene MT-CO1 and viral infectious disease.