The present application relates to the field of cancer. Surprisingly, it was shown that the Fragile X mental retardation gene (Fmr1) products such as the FMRP protein, primarily implicated in mental retardation, are upregulated in metastasizing tumours. It is shown how Fmr1 gene products can be used as a marker for cancer metastasis and how inhibition of these gene products may help prevent or reduce metastasis.
