In a recent xenotransplantation study with the 697 leukaemia cell line derived from a t(1;19)+ pre-B ALL patient [186], the aim was to investigate the role of autophagy in leukaemia development through rapamycin treatment which inhibits mTOR activity, since it is known that the activation of autophagy can downregulate E2A-PBX1 expression [187]. This evidence concerns the gene PBX1 and leukemia.