AKT1 and renal cell carcinoma: In opposition to the extensive data on bone metastasis of breast, prostate, and lung cancer, only little is known about the role of AKT in bone metastasis of other cancer entities, such as malignant melanoma, renal cell carcinoma, bladder cancer, hepatocellular cancer, colorectal cancer, gastric cancer, oral squamous cell carcinoma, or thyroid cancer.