MCM3AP (minichromosome maintenance complex component 3 associated protein) is a multifunctional protein that plays critical roles in DNA replication control and transcriptional regulation. The protein binds to and acetylates the replication protein MCM3, participating in the initiation of DNA replication and ensuring that DNA replication occurs only once per cell cycle. Through its histone acetyltransferase activity, MCM3AP affects nucleosome assembly at immunoglobulin variable region genes and promotes recruitment of transcription complexes to facilitate DNA cytosine deaminase AICDA/AID targeting, thereby promoting somatic hypermutations in immune cells. The protein is associated with various cellular processes including mRNA export from the nucleus and chr21 organization. MCM3AP is linked to peripheral neuropathy with or without intellectual disability when mutated. Additionally, the antisense RNA transcript MCM3AP-AS1 has emerged as a significant long non-coding RNA involved in cancer biology, with aberrant expression associated with tumor progression, metastasis, and poor prognosis across multiple cancer types 12. The MCM3AP-AS1 lncRNA functions as a competitive endogenous RNA, sequestering various microRNAs and affecting cancer-related signaling pathways including PTEN/AKT and PI3K/AKT 34.