Mechanisms of antitumor action of MH and its constituent compounds are suggested to include activity as selective estrogen receptor modulators (SERMs), inhibitors of growth factor receptor signaling pathways, and blockade of the proliferation of breast cancer stem/progenitor cells, which play a critical role in tumor regeneration and spread following treatment with standard therapies in the clinic [16,24,25,26]. The gene discussed is ESR1; the disease is breast carcinoma.