Thirdly, the loss of junctional RNAi in colon tumors and cell lines, taken together with our previously published findings in Caco2 cells and our current findings on HCT116 cells, suggests that the PLEKHA7-RNAi complex is a potential novel tumor suppressor mechanism, which acts to maintain colonic epithelial homeostasis. The gene discussed is PLEKHA7; the disease is colonic neoplasm.