It was demonstrated that patients with high mRNA levels of ABCA2, besides three other studied genes, were included in the group of patients with poor response to chemotherapy (53).Gillet and colleagues identified ABCA2 as one of the genes which was highly expressed in multidrug resistant cell lines of breast cancer( MCF7/CH1000), AML (HL60/AR) and T-ALL(CEM/ADR5000)[13]. The gene discussed is ABCA2; the disease is breast carcinoma.