PHF6 and myelodysplastic syndrome: However, in three cases (one MDS, one AML, and one PMF), mutations of PHF6 and SF3B1 had nearly equal VAFs and hence were likely in the same dominant clone; there were also no or fewer (≤2) other genes involved, with zero in PMF cases, one in an MDS case, and two in AML cases (Figure 2B).