TP53 and myelodysplastic syndrome: Del(5q) MDS bone marrow samples display increased apoptosis associated with an induction of TP53 in erythroid cells and upregulation of TP53 target gene expression.[12,13] Two commonly deleted regions (CDRs) exist at chromosome 5q33.1 (distal) and 5q31.2 (proximal) in patients with del(5q)-associated myeloid diseases.