Pairwise comparison of this “normal DNA” with AML samples followed two criteria: (1) the suggested germline variant (e.g. RUNX1) should show a variant allele frequency of nearly 50% in the normal DNA, (2) in contrast to the germline variant, additional genetic markers such as NRAS should only be present in the AML sample but not in normal DNA [30–32]. Here, RUNX1 is linked to acute myeloid leukemia.