ACE2 and COVID-19: Several findings involving methods such as network pharmacology and molecular docking techniques have also pointed out that the active ingredients of single herbal medicines such as glycyrrhiza, scutellaria baicalensis, Coptis chinensis and lonicera japonica, and compound herbal medicines such as Yinqiaosan and LianhuaQingwen capsule can act on different targets and pathways of COVID-19, such as angiotensin-converting enzyme 2 (ACE2), TNF signaling pathway, T-cell receptor signaling pathway, Toll-like receptor signaling and MAPK signaling pathway (91–95).