Interestingly, while late-generation mice doubly null for Atm and Terc (Atm–/–Terc–/–) have chromosomal instability, cachexia, and reduced survival, they are also tumor resistant with suppression of thymic lymphomas compared with early-generation (G0) double-mutant Atm–/–Terc–/– or single-mutant Atm–/– mice (63–65). This evidence concerns the gene TERC and thymus lymphoma.