PSMA-IN-1 (compound 23) is an inhibitor of PSMA with a K i value of 2.49 nM. PSMA-IN-1 inhibits tumor growth with high selectivity and specificity in PSMA+ xenograft models. PSMA-IN-1 is a NIR probe (λ EX : 620 nm; λ EM : 670 nm) used for tumor disappearance. PSMA-IN-1 can be used for research on prostate cancer.