CCL3 and COVID-19: The two CCs that were significantly lower in the COVID-19 cohort were MDC (158 ± 12 vs. 231 ± 26, pg/ml, p < 0.05) and MIP1a (2.5 ± 0.4 vs. 4.2 ± 0.8, pg/ml, p < 0.05).