MCM2 is a core component of the MCM2-7 replicative helicase complex, essential for DNA replication initiation and elongation in eukaryotic cells 1. As part of the CDC45-MCM-GINS (CMG) complex, MCM2 forms one of six ATPase active sites that unwind template DNA during replication 2. The MCM2-7 double hexamer is loaded onto chr3 during G1 phase to license replication origins, with MCM2 contributing differentially to overall helicase activity through conserved arginine finger motifs at subunit interfaces 3. MCM2 is required for S-phase entry and cell division, and plays developmental roles in cochlear hair cell differentiation 2. Clinically, MCM2 overexpression is detected across multiple cancer types and correlates with poor prognosis 4. In HBV-related hepatocellular carcinoma, YTHDF2-mediated stabilization of MCM2 transcripts promotes cell cycle progression and tumorigenesis 5. MCM2 dysfunction impairs DNA replication and genomic stability, positioning it as a potential biomarker for cancer diagnosis and prognosis 4. MCM2 inhibition shows anti-tumor potential and may enhance immunotherapy efficacy by inducing replication stress 6. Additionally, MCM2 mutations are associated with autosomal dominant deafness type 70, highlighting its importance in specialized cell types.