In a first-in-human study consisting of 26 tumor lesions in 20 patients with prostate cancer, Al[18F]-PSMA-Q had a T/M ratio of 44.77, which was higher than the previously reported T/M ratios of 18F-labeled PSMA agents, including [18F]-DCFPyL, [18F]-PSMA-1007, and [18F]-rh-PSMA-7. The gene discussed is FOLH1; the disease is neoplasm.