AR and carcinoma: In vivo confirmation of the AR- and AR-V7-dependent regulation of lactate synthesis in CRPC was independently obtained from data of hyperpolarized (HP) [1-13C]pyruvate, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS) performed in AR-dependent CRPC PDX models (AR/AR-V7-positive sublines MDA PCa 180 and 133-4 [52]) and AR-negative carcinomas with neuroendocrine features (sublines MDA PCa 155-2 and 144-13 [53]) [30].