CXCR4 and cancer: Despite the interest in using CTCE-9908 as a CXCR4 inhibitor for its anti-tumoural, anti-angiogenic, and anti-metastatic effects in different cancer preclinical models, the peptide has never been radiolabelled before (Gravina et al. 2015; Huang et al. 2009; Drenckhan et al. 2013).