Data from the study published by Eric et al [11] determined that patients younger than 40 years presented worse prognostic factors when compared with patients older than 60 years, among whom were reported grade 3 (29% versus 17%), oestrogenic receptor negativity (45% versus 23%), multicentric BC (23% versus 5%), triple-negative (32% versus 10%) and a higher proliferation index Ki-67 (25% versus 10%), p value < 0.05. The gene discussed is MKI67; the disease is breast cancer.