BCR and acute lymphoblastic leukemia: The following four chromosomal translocations with corresponding PGF and frequencies are common in childhood ALL: t(12;21)(p13;q22) TEL-AML1 (24–26%), t(1;19)(q23;p13) E2A-PBX (5–6%), t(9;22)(q34;q11) BCR-ABL p190 (3–5%) and t(4;11)(q21;q23) MLL-AF4 (∼5%).The number of chromosomal translocations resulting in PGF is constantly growing with usage of new powerful screening approaches [8].