To further characterise the AKT1 E17K mutation in human cancers, the following questions were investigated in this study: (a) whether human cancer tissues from various histologic origins have the AKT1 E17K mutation; (b) whether there is any ethnic difference of the AKT1 E17K mutation incidence in breast and colorectal cancers; and (c) whether any corresponding mutation of AKT1 E17K occurs in AKT2 or AKT3 genes. Here, AKT3 is linked to cancer.