S100A1 and COVID-19: Of note, 38 of 59 hub genes were broadly enriched in CD14+ monocytes compared to other cell types., which implied that CD14+ monocytes were the main source of cytokine storms in COVID-19, consistent with previous studies (53).Combined with the results from transcriptome analysis, we can infer that these hub genes such as Il1b, S100a, Il1rn and other inflammatory factors may be the main contributors to the cytokine storm in COVID-19 patients.