Interestingly, some studies have revealed the association of Cystatin SN (CST1) a cysteine protease inhibitor that protects against allergen and viral, and AKT pathway an important pathway that controls many cellular processes such as survival, cell division, and autophagy in suppression and progression of GC, and these previous results provided great potential for GC targeted therapy.6 Here, CST1 is linked to gastric cancer.