Therefore, we selected a panel of genes including IKZF1, CDKN2A/B, PAX5, BTG1, TBLXR1, RAG1, RAG2 and ETV6 that were described as being involved in the pathogenesis of B-ALL previously, we expanded the panel by adding genes that were found to have minor aberrations in patients of this cohort, and we analyzed gene copy number alterations in patients. This evidence concerns the gene PAX5 and precursor B-cell acute lymphoblastic leukemia.