A, intracellular NAD levels, NADase activity, and cell growth were determined in Panc-1 control stable clone and a Panc-1-CD38 clone. The expression of CD38 was evaluated by immunoblotting. B, Panc-1 cells and Panc-1-CD38 cells were used in an in vivo xenograft mouse model and the size of the tumors was measured during a three week period (n=5). * indicates p<0.05. C, Panc-1 control cells and Panc-1-CD38 cells were stained for β-Galactosidase. The expression of CD38 and P21 was evaluated in these cells by immunoblotting for Flag and P21. D, Panc-1 control cells and Panc-1-CD38 cells were grown in soft agar containing 1 nM FK866 for 7–10 days in triplicates. Results represent the mean ± SD of three independent experiments. Quantitative analysis of colony formation shows significant reduction (* p< 0.05, n=3) in colony number upon CD38 overexpression in comparison to empty vector; and (# p< 0.05, n=3) upon FK866 treatment in Panc-1-CD38 but not in Panc-1 control cells.