PIK3CD and COVID-19: In this part, we explore the action mechanism of CEP through the methods of NP and molecular docking technology, and find that CEP acts on the key targets such as AKT1, PIK3CA, PIK3CD, and ACE2 through PI3K-Akt signaling pathway, Relaxin signaling pathway, VEGF signaling pathway and HIF-1 signaling pathway to achieve the purpose of anti-COVID-19, which lays a foundation for the further study of CEP and drug screening for prevention and treatment of COVID-19.