CCL2 and COVID-19: Expanding on these observations, another study found that severely affected COVID-19 patients (n = 13) admitted to the intensive care unit (ICU) not only had higher plasma levels of IL-10 and TNFα compared to less severely ill patients not admitted to the ICU (n = 28) but also increased levels of IP-10, IL-2, IL-7, G-CSF, MCP1 and MIP1A [3].