Pictures of immunohistochemistry assays (200× magnification) performed with anti-FOXP1 antibody showing different levels of protein expression in the bone marrow biopsies of investigated cases. (a) patient under study (level 3); (b) normal BM (level 0); (c) MDS case no. 558/10 with del(5q) as a sole cytogenetic abnormality (level 1); (d) MDS case no. 7737 with del(5q) and trisomy 21 (level 2); (e) MDS case no. 2374 with del(5q) and monosomy 7 (level 3); (f) AML case no. 635/12 with normal karyotype (level 4). (see Additional file 1).