C3AR1 and infection: These hub genes were predominantly related to the regulation of neutrophil degranulation (ITGAM, ITGB2, and SPI1), dendritic cell chemotaxis (CCR5 and SPI1), follicular B cell differentiation (SPI1 and IRF8), synapse pruning (ITGAM and C1QB), integrin αM-β2 complex (ITGAM and ITGB2), the regulation of prostaglandin-E synthase activity (ITGAM and ITGB2), <i>Staphylococcus aureus</i> infection (ITGAM, ITGB2, C1QB, and C3AR1) and pertussis (IRF8).