MPP2 (MAGUK p55 scaffold protein 2) is a member of the MAGUK (membrane-associated guanylate kinase) family that functions as a scaffold protein in multiple cellular contexts. The protein contains characteristic MAGUK domains including L27, PDZ, SH3, and GuKc domains 1. MPP2 plays a role in cellular transformation, as demonstrated by its interaction with HPV16 E7 protein, where it enhances E7/Ha-Ras co-transformation of rat embryo fibroblasts and stimulates E7-mediated transcriptional activity 2. In colorectal cancer, MPP2 expression is negatively regulated by DNA methylation and serves as an independent prognostic risk factor, with high expression associated with poor prognosis 3. MPP2 knockdown significantly inhibits SW480 cell proliferation via the mTOR signaling pathway 3. The protein also shows involvement in immune regulation, demonstrating close relationships with immune checkpoint molecules and immune cell infiltration, particularly CD4+ T cells 3. Additionally, a de novo missense mutation (K315N) in MPP2 increases susceptibility to Vogt-Koyanagi-Harada disease through enhanced binding to ANXA2 and activation of the ERK3/IL-17E pathway 4. MPP2 has been identified as a potential antigen for colon cancer mRNA vaccines due to its immunological relevance 5.