Interestingly, no functional in vivo or in vitro models of AT/RT-TYR, characterized by the hemizygous loss of chr22, have been achieved.53,58,72 While the less aggressive behavior of AT/RT-TYR tumors might contribute to that, the reason why the experimental setups only give rise to AT/RT-MYC and AT/RT-SHH is intriguing. Here, TYR is linked to ataxia telangiectasia.