Kaempferol and quercetin were able to bind to ACE2 and modulate signal pathways such as prostaglandin-endoperoxide synthase 2 (PTGS2), caspase 3, B-cell lymphoma 2 (Bcl-2), and Kaposi’s sarcoma, all of which are linked to herpes virus infection, measles, hepatitis C, human cytomegalovirus, and Epstein–Bar. Here, PTGS2 is linked to Kaposi's sarcoma.