Assessment of the PSMA-derived total tumor volume before and after therapy in [68Ga]Ga-PSMA-11 PET/CT was first proposed by Schmuck et al. [12] and Schmidkonz et al. proved its efficiency in response assessment of PCa [13], similarly to other malignancies, mainly lymphomas, in [18F]FDG PET [14, 15]. The gene discussed is FOLH1; the disease is lymphoma.