We used routine blood tests and histopathologic analysis of BM, spleen, and liver to evaluate the hematologic and morphologic characteristics of Sf3b1+/− mice in the context of MDS by comparing the long term follow-up (15 months) of Sf3b1+/− and Sf3b1+/+ mice. The gene discussed is SF3B1; the disease is myelodysplastic syndrome.