CXCR4 and cancer: The T22‐GFP‐H6‐FdU nanoconjugate replicates the nanoparticle capacities for self‐assembling, lack of renal filtration, high re‐circulation in blood, and selective internalization in target CXCR4+ cells, which we described for T22‐GFP‐H6 (Unzueta et al, 2012a,b, 2015; Rueda et al, 2015; Céspedes et al, 2016) adding the ability to transport and intracellularly release FdU, which induces an increase in genotoxic damage and apoptosis, leading to selective CXCR4+ cancer cell elimination as well as to a reduction in tumor re‐initiation capacity.