GRPR and prostate cancer: Out of 171 prostate cancer patients, two patients with neuroendocrine differentiation prostate cancer (GS = 5 + 4 and GS = 5 + 3) did not express PSMA (see Table 2), one of whom was positive for CgA, CD56, Syn, and NSE, while the other was positive for CgA and CD56, and both of them exhibited positive NTR1 and GRPR, with especially high NTR1 expression.