MCM5 is a core component of the MCM2-7 replicative helicase complex, essential for DNA replication initiation and elongation 1. It functions as part of the CDC45-MCM-GINS (CMG) helicase, the molecular machine that unwinds template DNA during replication and serves as the foundation for replisome assembly 2. The complex's six ATPase active sites are formed through inter-subunit interactions involving conserved arginine finger motifs, with MCM5 contributing differentially to helicase activity. MCM5 UFMylation at Lys583 by the E3 ligase UFL1 is critical for efficient origin firing and replication fork progression; mutations blocking this modification destabilize the helicase complex and impair DNA replication 1. Beyond its canonical replication role, MCM5 is implicated in cancer progression through multiple regulatory pathways. m6A-dependent stabilization of MCM5 transcripts promotes cell cycle progression in hepatocellular carcinoma 3, colorectal cancer metastasis via epithelial-mesenchymal transition 4, and lung adenocarcinoma cellular plasticity through Notch signaling activation 5. MCM5 transcription is also suppressed by E2F2 degradation in cancer therapy contexts 6. Mutations in MCM5 are associated with Meier-Gorlin syndrome 8, and dysregulation correlates with poor prognosis in multiple cancers, making MCM5 a potential therapeutic target.