Together, this study demonstrated for the first time that helenalin, BHM, and BHG can inhibit tumor cell growth in vitro and regulate various signaling molecules, including STAT3, MYC, CDC25, CDK1, p53, and p21, and can potentially prevent the development of multidrug resistance in TNBC via ABC transporter inhibition. The gene discussed is ABCG2; the disease is neoplasm.