This corroborates with our data where, contrary to CCL2, serum CX3CL1 was quicky augmented suggesting that non-classical monocytes (NC; CD14+/-CD16++/CX3CR1+) rather than classic monocytes (CL; CD14++CD16−/CCR2+) are the first actors during COVID-19. The gene discussed is CX3CL1; the disease is COVID-19.