Its expression was >3-fold lower than PMCA1 and PMCA4 isoforms (Fig. 5A), which contrasts with rodent models of lactation where PMCA2 is the predominant isoform6, 17 and was consistent with our RNAseq cell line data of MDA-MB-231 and other Basal breast cancer cell lines. Here, ATP2B1 is linked to breast cancer.