In 5 of these patients, despite a negative 68Ga-THP-PSMA PET-CT scan, there is ongoing concern about micro-metastatic disease due to a continuing rise in PSA; 1 is having more intensive PSA surveillance (PSA 1.42 μg/L), 2 have commenced ADT (PSA 1.98 μg/L and 1.2 μg/L, respectively) and 2 are on chemotherapy (PSA 1.37 μg/L and 1.67 μg/L, respectively). The gene discussed is KLK3; the disease is metastatic neoplasm.