The present invention relates to methods of controlling tumorigenesis, including preventing, inhibiting, arresting or reversing tumorigenesis. The present invention also provides methods of treatment, prevention and diagnosis of neoblastoma, including cancer, such as metastatic cancer. In one method one or more cells having a predisposition to turn tumorigenic are identifyied. In the one or more cells an altered amount, an altered subcellular localisation or an altered activity of a Rab binding protein is detected. In a method of diagnosing the risk of developing a neoplasmt at least one of the expression level, the activity level and the subcellular localisation of a Rab binding protein is determined. In an in-vitro method of identifying a compound capable of forming a complex with a Rab binding protein the components that form the respective complex are contacted with each other. In a method of determining whether a neoplasm is sensitive to an alteration of intracellular calcium levels, at least one of the expression and the activity of a Rab binding protein is determined. An altered expression or an altered activity of the Rab binding protein is an indication that the neoplasm is sensitive to an alteration of intracellular calcium levels.
