KAT5 and ataxia telangiectasia: Among them are telomere fusion (tefu), the Drosophila orthologue of human ATM (Ataxia Telangiectasia Mutated); meiotic recombination 11 (mre11) and rad50, members of the MRN complex that activates ATM; and Nipped-A, pontin (pont), Tip60 and domino (dom), all of them components of the Tip60 complex, which is also a mandatory activator of ATM [58].