CXCR4 and neoplasm: By linking amino acid modifications and the N-terminal 99mTc-labelling strategy, Konrad et al. developed and comparatively assessed six mas3-conjugated CPCR4 (CXCR4-targeted ligand) analogs on the basis of pentixafor scaffold with N4-L6-CPCR4 (PentixaTec) having an enhanced hCXCR4 affinity of 0.6 ± 0.1 nM, [99mTc]Tc-PentixaTec had the highest internalization efficiency (97% of all cellular activities within 2 h) and the maximum tumour uptake (8.6 ± 1.3%ID/g, 1 h).