The addition of SM6Met to 4-OH-Tam at combination ratio’s 1:1 and 1:20, resulted in a further significant (p < 0.05) increase in the reduction of ER+ breast cancer cell invasion as compared to 4-OH-Tam or SM6Met alone, with the highest inhibition elicited by the 20:1 combination ratio. The gene discussed is ESR1; the disease is breast carcinoma.