ENTPD1 and COVID-19: All in all, however, the data on CD39 expression in the context of COVID-19 are relatively sparse, and there are no studies simultaneously investigating the purinergic signaling pathway, as well as a broader panel of ICPMs in COVID-19 patients in order to find independent prognostic biomarkers under the exclusion of other confounding laboratory and clinical parameters [22,23,24,25,26,27,28,29,30].