In a recent study, Lavin and colleagues examined cells from mice with disrupted Atm, Tdp1, Setx, or Aptx genes, which cause ataxia telangiectasia (AT), spinocerebellar ataxia with axonal neuropathy 1 (SCAN1), AOA2, and ataxia oculomotor apraxia type 1 (AOA1) disorders, respectively [15]. The gene discussed is TDP1; the disease is cerebellar ataxia.