To identify natural-source-derived pharmacological drugs that could be useful for cancer therapy by targeting STAT3 activation pathways, focus has been placed on acacetin isolated from plants, such as Tunera diffusa, Propolis, Dracocephalum moldavica, Betula pendula, Robinia pseudoacacia, Flos Chrysanthemi Indici, Chrysanthemum, Safflower, Calamintha, and Linaria species [16,17]. Here, STAT3 is linked to cancer.