SF3B1 and myelodysplastic syndrome: The high mean variant allele frequency (VAF) of SF3B1 found in studies shows that the SF3B1 mutation is present in dominant MDS clones, suggesting that the mutation itself originates from cells actively proliferating in the MDS clones (66), while it has been also proposed that the consecutive acquirement of genetic lesions with SF3B1 in one of the mutated major clones at the early stages of MDS is implicated in AML transformation (67).