BAG3 and neoplasm: In order to determine if BAG3 could regulate cell tumour proliferation in TNBC, the BAG3 gene was gene silenced in three TNBC cell lines that expressed high levels of BAG3 protein (MDA-MB-231, MDA-MB-468 and BT-549 cells) and the quantification efficiency of reduced BAG3 protein expression measured by densitometry (>80%) (Figure 3A).