In the next, we sought the expression of Sp1 and Sp3 in GC cells to clarify the regulatory mechanism underlying SHIP2 suppression, and found that in GC cell lines and in GC tissues Sp1 expression, but not Sp3, was commonly reduced compared with normal gastric mucosal epithelial cells or matched adjacent normal tissues, which is consistent with the data in the Human Protein Atlas (available on: http://www.proteinatlas.org/ENS00000185591/cancer, http://www.proteinatlas.org/ENS00000172845/cancer). This evidence concerns the gene SP1 and cancer.