In a RANKL-overexpressing LNCaP metastatic prostate tumor xenograft model, NIRF imaging detected two superficial tumors in a mouse after PC-1001 injection, while 64Cu-PC-1001 revealed an extra tumor in the same mouse, indicating that the enhanced tissue penetration of gamma radiation enables the detection of deep-tissue tumors [4]. This evidence concerns the gene TNFSF11 and prostate neoplasm.