Using single nucleotide polymorphism (SNP) arrays, many groups detected multiple submicroscopic CNA not evident on cytogenetic analysis, commonly less than one megabase (Mb) in size and targeting, in most of the cases, a single or few genes implicated in key cellular pathways, such as lymphoid development (IKZF1, PAX5, EBF1, VPREB1), cell cycle regulation and tumor suppression (CDKN2A/CDKN2B, PTEN, BTG1, RB1), lymphoid signaling (BTLA, CD200), drug responsiveness (NR3C1), and DNA mismatch repair (MTOR, HERC1, PRKCZ, and PIK3C2B) [5, 15–17, 18•, 19, 20]. This evidence concerns the gene IKZF1 and neoplasm.