MITD1 (microtubule interacting and trafficking domain containing 1) is a multifunctional protein with primary roles in cellular division and antiviral immunity. Structurally, MITD1 is required for efficient abscission at the end of cytokinesis through interaction with ESCRT-III complex components 1. Beyond this canonical function, MITD1 exhibits brain-specific interferon-inducible activity, functioning as a potent antiviral factor that inhibits replication of neurotropic flaviviruses including West Nile virus, Usutu virus, Zika, and dengue virus by sequestering ESCRT-III proteins needed for viral replication factory formation 2. This antiviral mechanism is particularly important in human microglia, where MITD1 mediates type I interferon-mediated defense against neurotropic flaviviruses. In cancer biology, MITD1 demonstrates paradoxical roles depending on tumor type. In breast cancer, elevated MITD1 expression associates with favorable prognosis, inhibiting cell proliferation and migration 1. Conversely, in kidney renal clear cell carcinoma and hepatocellular carcinoma, high MITD1 expression correlates with poor survival outcomes 34. MITD1 also modulates tumor microenvironment composition and immune infiltration patterns. In renal cell carcinoma, MITD1 expression regulates sunitinib sensitivity through the RBCK1-ANKRD35-MITD1-ANXA1 axis affecting AKT/MAPK signaling 5. MITD1 serves as a potential immunotherapy biomarker and may predict responses to platinum and PARP inhibitor therapies 1.