A recent study in mice has shown that inactivation of Smarcb1 can most efficiently cause tumors resembling atypical teratoid/rhabdoid tumours (AT/RTs), an agressive pediatric CNS cancer, when induced during an early window of pre-natal development (E6 to E10) (Han et al., 2016). This evidence concerns the gene SMARCB1 and ataxia telangiectasia.