{Reference Type}: Letter {Title}: The variable biological signature of refractory cytopenia of childhood (RCC), a retrospective EWOG-MDS study. {Author}: de Winter DTC;Langerak AW;Te Marvelde J;Dworzak MN;De Moerloose B;StarĂ½ J;Locatelli F;Hasle H;de Vries ACH;Schmugge M;Niemeyer CM;van den Heuvel-Eibrink MM;van der Velden VHJ; {Journal}: Leuk Res {Volume}: 108 {Issue}: 0 {Year}: 09 2021 {Factor}: 3.715 {DOI}: 10.1016/j.leukres.2021.106652 {Abstract}: