The anti-proliferation property of calycosin was demonstrated in the nasopharyngeal carcinoma cell lines CNE1 and CNE2 at the effective concentration of 8–50 μM via decreasing the expressions of lncRNA Ewing sarcoma-associated transcript 1 (EWSAT1) and the downstream (tumor necrosis factor receptor-(TNFR)-associated factor 6) TRAF6, p-TAK1, and p-IκBα/p-c-Jun pathways, which are involved in the development of inflammation and tumorigenesis. Here, EWSAT1 is linked to nasopharyngeal carcinoma.