ATP2C1 and breast cancer: Interestingly, based on clinical samples, Desma et al. reported SPCA1 levels to be significantly elevated in the basal subtype of BC compared with all other subtypes, and it is worth noting that changes in its expression affect posttranslational modification and transport of certain proteins important for tumor progression without significantly changing cytosolic calcium signaling; SPCA1 inhibition also decreased MDA-MB-231 cell proliferation [82].