In contrast to trisomy 13, deletion of chromosome 3q occurs in about 2% of MDS cases   57 .The RB1 gene, a tumor-suppressor gene involved in cell-cycle control and cellular differentiation, is located in the deleted regions of cells with del(13q)   58 .There is a strong association between the occurrence of del(13q) and therapy-related MDS and therapy-related AML, foreshadowing poor outcomes in this patient subgroup 57, 59 . Here, RB1 is linked to myelodysplastic syndrome.