A method of preventing tumor metastasis with the proviso that the tumor is not glioma is provided. The method comprising administering to a subject in need thereof a therapeutically effective amount of an inhibitor of synaptojanin 2 (SYNJ2), thereby preventing tumor metastasis. Also, provided is a method of treating cancer. The method comprising, administering to a subject in need thereof a therapeutically effective amount of an inhibitor of synaptojanin 2 (SYNJ2) and an inhibitor of a cell surface receptor associated with an onset or progression of cancer, thereby treating cancer.