In conjunction with the clinical studies cell experiment studies will be carried out on induced pluripotent stem cell (IPSC) derived hepatocytes from individuals with A-T, to assess drug response at a cellular level. This will be a collaboration with the Sanger Institute in Cambridge, where they have already developed IPSC-derived hepatocytes from the blood of A-T patients. These cells will be used to create a drug response model at a cellular level. These cell lines are not from our recruited patients directly, but serve as a cellular model of A-T. However, we will offer the A-T group the chance to donate blood to the INSIGNIA study, run by the Sanger Institute, which is a study focused on the investigation of patterns of mutations (signatures) in inherited and other progressive genetic diseases (please see INSIGNIA PIS and consent forms). This is optional and taking part in RAMP does not commit those with A-T to contributing to INSIGNIA.