More recently, Schaub and colleagues disputed this result using colony formation assays to show that TET2 mutations can either precede (4 of 8 patients), follow (2 of 8), or occur independently (2 of 8) of JAK2 V617F mutations in MPN patient samples (Schaub et al., 2010). The gene discussed is JAK2; the disease is myeloproliferative neoplasm.