NFKB1 and myelodysplastic syndrome with single lineage dysplasia: Kerbauy et al. [9] found that patients with low grade/early stage MDS [refractory anemia/refractory anemia with ring sideroblasts (RA/RARS)] had low NF-κB activity levels that were comparable to those in normal marrow, while patients with RA with excess blasts (RAEB) had significantly increased NF-κB activity levels.