CXCR4 and Familial prostate cancer: There is evidence that CXCL12/CXCR4 signalling associated with lipid rafts is important in driving prostate cancer cell metastasis in bone39 but there is no evidence that drebrin associates with lipid rafts.40 Co-ordination of the microtubule and F-actin cytoskeletons mediated by the drebrin/EB3 pathway occurs in filopodia leading to their stabilization in response to extrinsic cues.3 There is mounting evidence that filopodia are important in the polarization and guided movement of cancer cells in 3D and in cancer metastasis and invasion,41 an idea supported by the findings reported here.