In co-culture experiments by Bebawy et al. 23 it was reported that a resistant acute lymphoblastic leukaemia cell line (VLB100), overexpressing the MDR1/P-gp gene, released and transferred MVs containing functional P-gp to a sensitive acute lymphoblastic leukaemia cell line (CCRF-CEM). This evidence concerns the gene ABCB1 and acute lymphoblastic leukemia.