CXCR4 and neoplasm: [68Ga]Pentixafor positron emission tomography (PET) is a well-established method to image CXCR4 expression of hematopoietic and solid tumors in vivo [14–16] and previous studies with [68Ga]Pentixafor have revealed a wide heterogeneity of tumor CXCR4 expression within different entities of cancer [17–19].