We found that most of the metabolic reactions within 11 metabolic pathways are upregulated in CCL2+ T cells and Group 2 macrophages in COVID-19 patients compared with HCs, but metabolic activity is similar in in CCL2+ T cells, Group 2 macrophages, and mDCs in severe and moderate COVID-19 patients (Figure 6C). Here, CCL2 is linked to COVID-19.