ABCG2 and breast carcinoma: Moreover, upregulation of BCL2 and ABCG2 was also demonstrated in both HCT-KOEP300 cells and its paclitaxel-resistant derivative (Fig. 6b, c), indicating that regulation of these two important molecules involved in apoptosis response/drug resistance and stemness is not breast cancer specific and probably represents major EP300-regulated pathways.