Algorithms for diagnostic questions using these methods in varying combinations are helpful to gather all relevant information in an effective way (Haferlach et al, 2005a) and allow the selection of disease-specific therapeutic approaches, for example, use of all-trans retinoic acid in acute promyelocytic leukaemia (APL) with PML-RARA, of imatinib in BCR-ABL-positive acute lymphoblastic leukaemia (ALL), or of specific antibodies against the CD20 or CD52 antigens. Here, ABL1 is linked to acute lymphoblastic leukemia.