Quercetin and EGCG was synergistic and inhibited cells’ upregulation of inducible nitric oxide synthase (iNOS) and intercellular adhesion molecule-1 (ICAM-1) in response to cytokine-induced iNOS and ICAM-1 levels induced by JAK–STAT activation in cholangiocarcinoma cells. According to recent studies on primary effusion lymphoma (PEL) cells, quercetin inhibits the STAT3 and PI3K/Akt/mTOR pathways, thereby downregulating prosurvival cellular proteins, including cMyc and cyclin D1. Furthermore, quercetin decreased the IL-6 and IL-10 release, resulting in PEL cell death [96]. This evidence concerns the gene NOS2 and primary effusion lymphoma.