Taken together, these observations indicate that SERCA3 expression is lost during the multi-step process of colon carcinogenesis, that decreased SERCA3 expression is an early marker of colon tumorigenesis, and that SERCA3 expression is induced during colon and gastric cancer cell differentiation, a process during which the calcium homeostasis of the cell is modified. Here, ATP2A3 is linked to digestive system neoplasm.