NLRP3 and COVID-19: We similarly incubated THP-1 cells (a human cell line derived from an acute monocytic leukemia patient, with or without phorbol myristate acetate (PMA) treatment) with exosomes from plasma of COVID-19 patients or those of healthy subjects, and a detectable change of NLRP3 inflammasome signaling change was not observed (see Fig. S1 in the supplemental material).