Dissecting the cell of origin of aberrant SALL4 expression in myelodysplastic syndrome

Dear Editor,Despite the increased reports on oncofetal protein Spalt like transcription factor 4 (SALL4) in myelodysplastic syndrome (MDS), the cellular identity of its aberrant expression in MDS patients remains unknown.Uncovering the answer to this question has important implications for furthering our understanding of the pathogenesis of F I G U R E 1 SALL4 RNA and protein were expressed in MDS bone marrow cells.(A) SALL4 expression in MDS CD34 positive cells from the public database GSE19429.(B) SALL4 expression in CD34 positive cells in MDS subtype from the public database GSE19429.RA, refractory anemia; RARS, refractory anemia with ring sideroblasts; RAEB1, refractory anemia with excess blasts1; RAEB2, refractory anemia with ring sideroblasts2.(C) MMI of SALL4 in bone marrow cells on CyTOF (MDS patients, n = 10, control BM, n = 5, error bars indicate standard deviation).Data analysis used Mann-Whitney U test.*p ≤ .05;**p ≤ .01. ns, not significant; HSPC, hematopoietic stem and progenitor cell; HSC, Hematopoietic stem cell; HPC, hematopoietic progenitor cell; MPP, multipotent progenitors, CMP; common myeloid progenitor; GMP granulocyte-monocyte progenitor; MEP, megakaryocyte-erythrocyte progenitor; NK cell, natural killer cell; MMI, median metal intensity.