NT5E and neoplasm: Next, since the presence of extracellular NAD+ and/or NMN in the fluids surrounding the tumor represents a fundamental pre-requisite to verify the hypothesis that interfering with the utilization of extracellular NAD+/NMN by inhibiting CD73 activity could enhance the anti-tumor activity of FK866, we measured NAD+ and NMN levels in the ascitic exudates collected from the animals at sacrifice.