m6A reader protein YTHDC1 promotes leukemogenesis by stabilizing m6A-marked MCM4 mRNA. YTHDC1 is highly expressed in malignant hematopoietic cells, which contributes to preservation of MCM4 transcripts. This leads to stabilization of the replication initiation complex through adequate levels of MCM4, which in turn supports the rapid proliferation of malignant hematopoietic cells.