CCL2 and COVID-19: Among individuals who develop severe COVID-19 in our cohort, we observe unique recruitment of highly inflammatory macrophages that represent the major tissue sources of proinflammatory cytokines including IL1B, TNF, CXCL8, CCL2, CCL3, and CXCL9/10/11—of likely relation to the immune dysregulation characterized by elevation of the same factors in the periphery in severe disease and observed in lung tissue among those who succumbed to COVID-19 (Delorey et al., 2021; Lucas et al., 2020).