PDCD4 and gastric cancer: Immunohistochemical staining of PDCD4 and Ki-67 in gastric cancer tissues and normal adjacent tissues also revealed the presence of higher proliferative activity (indicated by the staining intensity of Ki-67-positive cells) but lower PDCD4 levels (indicated by the staining intensity of PDCD4-positive cells) in the gastric cancer tissues (Figure 2e).