DS-MB-01916 is specific for nonclassical MHC class I chain A (MICA) and nonclassical MHC class I chain MICB (MICB). MICA and MICB are stress inducible antigens, which are closely related and appear functionally indistinguishable. MICA and MICB are ligands for NKG2D, an activating receptor on most natural killer (NK) cells, CD8 T cells and gamma delta T cells. MICA is principally expressed on intestinal epithelium, and several epithelial tumours. Expression may be induced to high surface levels by heat shock, oxidative stress, and virus infection. DS-MB-01916 is reported to inhibit the cytotoxicity of NK cells stimulated by IFN alpha-treated dendritic cells (6).