CCL3 and COVID-19: Previous studies have reported severe humoral immune imbalances and cytokine storms in severe COVID-19 as well as the important role of monoclonal antibody therapy targeting certain cytokines.46,47 Here, we observed the differentiation of naive EGR1+ monocytes into CCL3+ monocytes at the early stage of bone marrow myeloid recruitment after Omicron infection and found the same transition in influenza patients, elucidating that EGR1+ monocytes may be the source of the cytokine storm following viral infections.