Cheng et al. (2021) reported one patient with TET2 mutations who developed metachronous JAK2-positive PV followed by AITL. In such examples, no studies have been done showing what determines which type of malignancy will develop first. Indeed, the available data in the current case do not provide for an established “order” of clonal relatedness following the apparent founder effect exhibited by the mutation in TET2 p.H1382R. This evidence concerns the gene JAK2 and acquired polycythemia vera.