A recent genome wide single nucleotide polymorphism (SNP) array analysis of Ph positive samples - 43 ALL (paediatrics and adults) and 23 CML (11 CP, 9 BCM and 3 BCL) [14] - revealed the presence of three common deletions affecting the IKZF1, PAX5 and CDKN2A loci. Here, IKZF1 is linked to blue cone monochromacy.