RUNX1 and Thrombocytopenia: Additional evidence for the role of EVI1 in megakaryopoiesis is supported by a recent study showing that a mutation, creating an EVI1 binding site, discovered by exome sequencing in the promoter of the RBM8A (RNA binding motif protein 8A) gene can underlie the thrombocytopenia with absent radii (TAR) syndrome 79.