Administration of AMD3100, a C-X-C chemokine receptor type 4 (CXCR4) inhibitor, in combination with the inhibitory checkpoint antagonist anti-PD-L1 (anti-programmed death 1 ligand 1), results in the loss of p53-positive tumour cells and in the accumulation of CD3+ T-cells (see Box 2) in the tumour area (Feig et al., 2013). This evidence concerns the gene CXCR4 and neoplasm.