ABCB1 and breast cancer: The ubiquitous expression of the dbpB/YB-1 gene in human normal and neoplastic tissues has been well studied and found to be closely associated with the expression of p-glycoprotein, the product of the multidrug resistance 1 (MDR1) gene, in breast cancers (Bargou et al, 1997), osteosarcomas (Oda et al, 1998), ovarian cancers (Kamura et al, 1999), and synovial sarcomas (Oda et al, 2003).