In addition to these well-studied and clinically relevant genes, novel target structures for theranostic approaches such as C-X-C Motif Chemokine Receptor 4 (CXCR4) and Fibroblast Activation Protein Alpha (FAP) emerged, with a growing spectrum of radioligand therapies in different cancer entities [4,5]. The gene discussed is CXCR4; the disease is cancer.