SPP1 and COVID-19: Of particular interest, our regulator effector analysis in severe-COVID-19 BAL cells revealed activation of CCL2, CCL3, CCL3L1, CCL4, CCL7, CCL8, CXCL8, SPP1, S100A8, and S100A9, and inhibition of MT-ND1 and FN1 upstream regulators which is predicted to trigger the chemotaxis of phagocytes and cellular movement of neutrophils in severe-COVID-19 BAL cells (Figure 8b,c).