A reduction in PTEN expression was detected in 13 of the 15 (86.7%) primary gastric cancer samples (in a range of 0.07–1.46, mean = 0.59, p < 0.001), though ten cases (66.7%) showed an increase in the proportion of phosphorylated PTEN in gastric cancer tissues compared with the paired adjacent mucosa (in a range of 0.48–2.26, mean = 1.29, p < 0.05) (Figure 1). Here, PTEN is linked to gastric cancer.