Specifically, the critical COVID-19 dominant cluster1 showed a decrease in incoming signaling for ITGB2, ANNEXIN, ADGRE5, SN, and THBS, and a decrease in outgoing signaling for MHC-II, MHC-I, ICAM, TNF, BAFF, SN, GRN, and BAG (Fig. 5B, C), thus incompetent in immune-crosstalk. Here, ITGB2 is linked to COVID-19.