PIK3CA and COVID-19: They were mainly involved in the Pathways in cancer, Neuroactive ligand-receptor interaction, Lipid and atherosclerosis, PI3K-Akt signaling pathway, Calcium signaling pathway, Human cytomegalovirus infection, AGE-RAGE signaling pathway in diabetic complications, cAMP signaling pathway, Coronavirus disease-COVID-19, Rap1 signaling pathway, Endocrine resistance, MAPK signaling pathway.