Fig. 4: High PMN-MDSC frequency associate with COVID-19 fatal outcome.

A PMN-MDSC frequency at the time of admission grouped in survivors (n = 59) and non-survivors (n = 19). Results are shown as Box and Whiskers. Mann–Whitney test was applied, and a p value < 0.05 was considered significant. B Receiver operating characteristic (ROC) curve for the PMN-MDSC frequency as marker of COVID-19 fatal outcome.