MICB (MHC Class I Polypeptide-Related Sequence B): MICB is a stress-induced ligand for the NKG2D receptor, which is expressed on natural killer (NK) cells, CD8+ T-cells, and certain γδ T-cells. The interaction between MICB and NKG2D is essential for immune surveillance, helping the body recognise and eliminate malignant or infected cells. Upregulation of MICB on stressed, transformed, or infected cells can activate an immune response, leading to targeted cell destruction. Therefore, MICB plays a key role in defence against cancer and viral infections.