PLAU and metastatic malignant neoplasm in the lymph nodes: In order to demonstrate the universal applicability of 89Zr-Df-ATN-291 in different cancer types and correlate its tumor uptake with uPA expression level in vivo, we expanded the PET studies in five more tumor models, including BxPC-3 (pancreatic adenocarcinoma), DU-145 (prostate carcinoma, derived from brain metastasis), SKOV-3 (ovarian adenocarcinoma), LNCaP (prostate adenocarcinoma, derived from lymph node metastasis), and MDA-MB-231 (triple-negative breast adenocarcinoma, derived from pleural metastasis).