ABCB7 and myelodysplastic syndrome with ring sideroblasts: Moreover, restoration of ABCB7 levels by cDNA overexpression in CD34+ BM cells from RARS patients appears to functionally rescue impaired in vitro erythroid colony output (although the morphological effect of ABCB7 modulation on ringed sideroblasts themselves was not evaluated in those assays) (Nikpour et al. 2013).