Currently, the majorityof STAT3 inhibitors merely inhibited STAT3Tyr705 phosphorylation, and most of them had poor inhibitory activities.So, we compared the inhibitory activity of a STAT3 dual-phosphorylationinhibitor YY002, with the several representative STAT3 inhibitorsincluding STAT3-SH2D inhibitors (C188-9, BP-1–102, Stattic,FLLL32), JAK2 inhibitor (AZD1480), and STAT3 and cancer stemness inhibitor(BBI-608). This evidence concerns the gene JAK2 and cancer.