PDC and COVID-19: Correlation analysis between IL-6 serum levels and the distribution of all DC subtypes further showed that in COVID-19 patients, IL-6 was negatively relatedto the circulating absolute levels of the CD1c+ cDC2 subpopulation (r = −0.29, p = 0.034) and CD303+ pDC subsets (r = −0.29, p = 0.036).