MYO1G (myosin IG) is a multifunctional protein with roles in immune recognition and cellular motility. As a minor histocompatibility antigen (mHag), MYO1G constitutes the HA-2 epitope, which when processed and presented on MHC class I molecules (specifically HLA-A*0201), can trigger T-cell-mediated immune responses 1. This immunogenic function is particularly relevant in hematopoietic stem cell transplantation, where MYO1G mismatches between HLA-matched donors and recipients can precipitate graft-versus-host disease (GVHD). At the cellular level, MYO1G functions in actin-dependent processes including cytoskeletal organization, cell migration, and phagocytosis through Fc-gamma receptor signaling. Recent evidence demonstrates MYO1G's involvement in cancer biology: the lncRNA MNX1-AS1/POU2F2/MYO1G axis regulates cancer stem cell properties and proliferation in lung cancer 2. MYO1G expression levels serve as a prognostic biomarker—overexpression associates with high-risk pediatric acute lymphoblastic leukemia and predicts relapse 3, while downregulation in SMARCA4-mutated lung cancers correlates with impaired antigen presentation and immunotherapy resistance 1. Additionally, MYO1G DNA methylation patterns are sensitive to environmental exposures (maternal smoking, second-hand smoke, prenatal stress) and associate with inflammatory bowel disease susceptibility 456. MYO1G methylation status also shows potential as a colorectal cancer biomarker 7.