This is, to our knowledge, the largest analysis (N = 15) published to date assessing the ability of [89Zr]Zr-PSMA-617 PET/CT to characterize as suspicious or non-suspicious for prostate cancer lesions that were indeterminate on recent prior [68Ga]Ga-PSMA-11 PET/CT. The gene discussed is FOLH1; the disease is Familial prostate cancer.