CCL4 and COVID-19: Muri et al. [30] showed that elevated levels of specific chemokines (such as CCL2, CCL3, CCL4, CCL7, CCL8, CCL19, CXCL2, CXCL5, CXCL8, CXCL9, CXCL10, CXCL13, CXCL16, and CXCL17) are present in acute COVID-19 cases, and recent multi-omics studies have identified plasma chemokines as among the most influential factors associated with COVID-19 severity.