ATP2B4 and cancer: In addition, we and others demonstrated that besides the BRAF/MEK/ERK pathway the expression of PMCA4b is also modulated by estradiol in ER+ MCF-7 breast cancer cells [18] and histone acetylation in breast [19] and colon [20,21] cancers and in melanoma [22] suggesting that the expression of this pump is under tight control.