By intersection analysis of PPI cluster genes and overlapping WGCNA module genes, four hub-shared genes in IS and COVID-19 were obtained, including phosphodiesterase 5A (PDE5A), integrin subunit beta 3 (ITGB3), CEA cell adhesion molecule 8 (CEACAM8), and bactericidal permeability increasing protein (BPI). The gene discussed is CEACAM8; the disease is COVID-19.