Commonly deleted chromosomal regions in MPN that map to single-target genes. Red horizontal bars indicate deletions; dark red, homozygous deletion; and blue, UPDs. (A) Recurrent deletions on chromosome 4q target the TET2 gene. (B) Complexity of chromosome 7 aberrations in MPN. The CDR on 7p (IKZF1) and 7q (CUX1) are shown. Two events of 7qUPD associated with an EZH2 mutation (*) are shown in blue. Another 7qUPD is negative for EZH2 mutations but has homozygous CUX1 deletion. Two overlapping deletions in the CUX1 gene locus and the homozygous deletion of CUX1 are shown at higher magnification. (C) Five overlapping deletion events on chromosome 3p define the target gene as FOXP1. (D) Recurrent deletions on chromosome 12. The target of 12p deletions is ETV6, whereas 1 of the commonly deleted regions on 12q contains CUX2. (E) Aberrations on chromosome 21q affecting RUNX1: single-gene deletion of RUNX1 and trisomy 21 with 2 nonsense mutations in RUNX1. chr indicates chromosome and Mbp, mega base pairs.