Other teams have also noted associations of various polymorphic forms of the MMP-3 gene with lymph node involvement in a population of South Indian women [48], or higher staging and ER/PR-negative BC type in a population of Native American women [49]; however, interpreting the impact of polymorphism is extremely difficult, as the gene polymorphism is greatly influenced by the ethnicity of the patients [11]. The gene discussed is ESR1; the disease is breast cancer.