PTGS2 and COVID-19: Moreover, in the PPI network, the top 13 targets, including BCL2L1, PTGS2, TP53, CASP3, CXCL8, EGFR, CSF2, MAPK14, TNF, VEGFA, MCL1, MAPK1, and IL1B, were selected as core targets that may play vital roles in emodin against COVID-19.