CCL18 and COVID-19: More importantly, CHIR-M-MØ exhibited a significant positive enrichment of the gene sets that define the COVID-19 lung pathogenic macrophages CD163+/LGMN+, MoAM3, and SPP1+ (Figure 2D) as well as enhanced production of profibrotic soluble factors like CCL2, IL-10, LGMN, CCL8, CCL18, and SPP1 (Figure 2, E and F), whose expression is markedly elevated in pathogenic lung macrophage subsets in COVID-19.