MICA (MHC class I polypeptide-related sequence A) is a membrane-bound stress-inducible ligand that plays a crucial role in immune surveillance by activating natural killer (NK) cells and CD8+ T cells through the NKG2D receptor 1. The protein is upregulated under cellular stress conditions and serves as a danger signal to alert the immune system 2. MICA functions by binding to the NKG2D receptor on immune effector cells, triggering cytotoxic responses and cytokine production that lead to tumor cell elimination 3. However, tumor cells can evade immune recognition through proteolytic shedding of MICA from the cell surface, generating soluble MICA (sMICA) that blocks NKG2D activation and promotes immune escape 4. Two major functional types of MICA polymorphisms exist, with Type-I variants showing stronger NKG2D binding and enhanced NK cell activation compared to Type-II variants 5. The gene exhibits significant polymorphism with disease associations, including susceptibility to schizophrenia in certain populations and rosacea 67. Therapeutically, antibodies targeting MICA's α3 domain can prevent shedding and restore immune recognition, while mRNA vaccines encoding MICA epitopes show promise in blocking tumor metastasis 28.