Our data show that Prdm1 suppresses IFN-γ-mediated gene transcription, and its induction inhibits IFN-γ-stimulated cell-intrinsic defense against Cryptosporidium, an apicomplexan parasite and a leading cause of infectious diarrhea and diarrheal-related death in young children worldwide. This evidence concerns the gene PRDM1 and dysentery.