These studies show that 68Ga-Pentixafor does accumulate in prostate cancer; however, studies comparing this tracer to 68Ga-PSMA are needed to see if CXCR4 targeted imaging and therapy can replace PSMA, especially with the suboptimal response of 177Lu-PSMA in patients with bone metastasis. The gene discussed is CXCR4; the disease is Familial prostate cancer.