MPPE1 and COVID-19: As expected, classical monocytes (cMono) represented the largest fraction of the myeloid compartment, particularly in the COVID-19 group, which correspondingly showed a significant reduction in the percentage of cDC1, cDC2, pDC, and particularly of non-classical monocytes (NcMono1 and NcMono2) compared to HD, LC, and Recovered individuals (Figure 2A).