CD274 and COVID-19: Remarkably, we found higher expression of CD86 and HLADR and lower expression of PD-L1 in the Ki67+ fractions of cDC2 and DC3 (Fig 5F and 5G), suggesting that the PD-L1hi CD86lo phenotype in DCs of COVID-19 patients was not caused by the recruitment of immature progenitors from the bone marrow, but could have been induced by external factors such as inflammatory mediators in the blood.