To further confirm our hypothesis that tumor MTAP deficiency leads to antifolate sensitivity, we carried out in vivo experiments in xenograft models of UC, which demonstrated that the MTAPprof HT-1376 tumor was resistant to pemetrexed (Fig. 2d) whereas the MTAPdef UM-UC-3 tumor was sensitive to pemetrexed (Fig. 2e). The gene discussed is MTAP; the disease is neoplasm.