Disruption of [Ca2+]cyt homeostasis induced by abnormal [Ca2+]cyt regulators, especially enhanced Ca2+ entry mode of NCX1, has been detected in some cancers, such as pancreatic cancer [18], breast cancer [29], penile cancer [30], and cervical cancer [31], indicating an significant role of NCX1 in tumorigenesis. This evidence concerns the gene SLC8A1 and breast cancer.