People aged between 2 and 45 (apart from children under the age of 16 who have acute myeloid leukaemia, juvenile myelomonocytic leukaemia (JMML) or MDS) will have conditioning with fludarabine, cyclophosphamide and radiotherapy to the whole body (total body irradiation). This takes 9 days all together. On the last day, you have the stem cells through a drip into a vein.