Although biallelic mutation is required for AML with biallelic mutation of CEBPA, it is technically impossible for either Sanger sequencing or routine (non-long-range) NGS to definitively delineate whether the concurrent N- and C-terminal mutations are biallelic, as they are far apart on different amplicons (Sanger sequencing) or sequencing reads (by NGS), and may reflect true biallelic events occurring on separate alleles (in trans) in the same cell, or two mutations involving the same allele (in cis), or distinct occurrences in separate subclones. Here, CEBPA is linked to acute myeloid leukemia.