Pervanadate, a pharmacologic phosphatase inhibitor, was used previously to validate the inhibitory effect of SHP-1 in STAT3-activated cancer [13, 14] In this study, pervanadate was used to investigate the role of SHP-1 in the dephosphorylation of JAK2/STAT3 and the anti-EMT effect of ATO. The gene discussed is STAT3; the disease is cancer.