Atypical teratoid/rhabdoid tumour (AT/RT) is typically characterised by loss of expression of the SMARCB1 gene product integrase interactor 1 (INI1) protein, but three 3 molecular subtypes are also presented (AT/RT-SHH, AT/RT-TYR and AT/RT-MYC) with potential prognostic and predictive significance [31]. The gene discussed is SHH; the disease is ataxia telangiectasia.