To investigate whether Bal-flavonoid treatment could increase Bal-induced ER stress in HepG2 cells and activate this pathway in breast cancer (MCF-7) cells, we evaluated the expression of CHOP and GRP78 in Bal-flavonoid (Nar, Nir, and Qu) treated HepG2 and MCF-7 cells. This evidence concerns the gene DDIT3 and breast cancer.