The biodistribution of [201Tl]Tl-pypa-PSMA was studiedin SCID/beige mice bearing either (i) DU145 PSMA-expressing tumors(PSMA-positive) or (ii) DU145 tumors that do not express the PSMAreceptor (PSMA-negative) to determine if [201Tl]Tl-pypa-PSMAaccumulated in prostate cancer tissues via PSMA receptor binding.This model has previously been used to show the PSMA-specific uptakeof tracers.36 Each group of mice was administered[201Tl]Tl-pypa-PSMA (10.7–24.5 MBq, 20 nmol) priorto SPECT/CT scanning for 2 h. Here, FOLH1 is linked to prostate carcinoma.