Other studies have shown that tanshinone IIA significantly downregulated the viability of ER-positive human breast cancer cells (MCF-7) and ER-negative human breast cancer cells (MDA-MB231) by dose- and time-dependent manners in vitro through downregulating the expression of P53 and Bcl-2 (Lu et al., 2009). The gene discussed is TP53; the disease is breast carcinoma.