MCM2 is one of the highly conserved mini-chromosome maintenance proteins (MCM) that are involved in the initiation of eukaryotic genome replication. MCM2 plays a crucial role in the regulation of DNA replication, ensuring that DNA is replicated only once during each cell cycle. MCM2 is particularly important as MCM2 forms part of the MCM2-7 complex, which acts as a helicase to unwind DNA, a critical step for the initiation of DNA replication. This unwinding is essential for proper genome duplication, and any dysregulation can lead to genomic instability, a hallmark of many cancers. MCM2 expression increases during cell growth, peaking at the transition from G1 to S phase of the cell cycle, and is tightly regulated by E2F transcription factors and various protein kinases.