Can any doc tell me what's mds rars and is it a sign of bone marrow failure?

See below...: Myelodysplastic syndrome (mds) is a form of bone marrow cancer that is generally less aggressive than leukemia but still malignant. Refractory anemia with ringed sideroblasts (rars) is a form of mds that is generally low grade. In mds the bone marrow generally has high cellularity whereas in bone marrow failure (aplastic anemia, aa) it has low cellularity. Aa is usually not clonal (not cancer).