In vivo CTL responses are normal in wild type, DPP IV and des-flurositagliptin treated mice. Specificity of CTL mediated killing was calculated by the formula described in Materials and Methods. FK506 was dosed S.C. for 3 consecutive days starting one day before priming. Des-flurositagliptin was milled in the chow and was given a day before priming and maintained through out the experimental duration (n = 8). These data are representative of 3 independent experiments.