CXCR4 and neoplasm: Moreover, AMD3465 has been radiolabelled with fluorine-18, being the most promising candidates 18FMCFB (high CXCR4 binding and selectivity) [146], 18FRPS-547 and 18FRPS-5324, the latter exhibiting superior tumour-to-normal tissue ratios when compared to 68Ga-Pentixafor in vivo [147].