In the first case, C/EBPα is a transcription factor that regulates myeloid gene expression in the hematopoietic system and its deficiency leads to a complete block of terminal myeloid differentiation at the pregranulocyte/monocyte‐cell stage.108 Frameshifts in the N‐terminal part of the C/EBPα coding sequence which results in expression of a shorter C/EBPα (p30) was reported in AML patients.109 p30 interacts with WDR5, colocalizes with H3K4me3 and mediates myeloid differentiation block in a WDR5‐dependent manner. The gene discussed is WDR5; the disease is acute myeloid leukemia.