In the last decade hybrid PET/CT imaging with PSMA radioligands has become widely accepted as a robust imaging modality in the setting of PC biochemical relapse after radical prostatectomy or radiotherapy (Calais et al. 2019; Fendler et al. 2019; Giesel et al. 2019; Strauss et al. 2021). The gene discussed is FOLH1; the disease is pachyonychia congenita.