AKT1 and colorectal cancer: Treatment with combinations of Ad-PTEN (adenovirus mediated PTEN gene transfer) and caffeine selectively induced the synergistic suppression of cell growth and apoptosis in colorectal cancer cells, but not in normal cells, through abrogation of G2/M arrest, downregulation of the Akt pathway, and modulation of the p44/42MAPK pathway.