While the ideal time point to assess PSA response after Lu-PSMA therapy and the ideal approach in prostate cancer therapy in general have both been a subject of debate for quite some time [20], it is generally accepted that an early increase in PSA values for at least 4 weeks can reflect tumor cell degradation, which reflects, among other factors, the flare phenomenon observable on bone scintigraphy. This evidence concerns the gene FOLH1 and prostate cancer.