In results similar to those of Abdel-Wahab et al. in mice (Abdel-Wahab et al., 2013), we show that tet2 and asxl1 cooperate in the pathogenesis of myeloid malignancies in zebrafish, although the phenotypes in zebrafish that we report are focused on MPN progressing to AML, rather than progressive MDS as observed in the murine model. This evidence concerns the gene ASXL1 and acute myeloid leukemia.