Mutation of mammalian diphthamide synthesis genes affects cell proliferation and development: inactivation of DPH3/KTI11 is associated with tRNA modification defects and neurodegeneration and mutations in DPH1/OVCA1 revealed a tumor suppressor role for this diphthamide synthesis gene in ovarian cancer [27], [38]–[40], [72]. This evidence concerns the gene DPH1 and neoplasm.