Natural killer cells are immunologically competent cells with cytolytic activity against tumor cells and cells infected by viruses or bacteria. Histologically, they reveal pale cytoplasm filled with azurophilic granules. CD56 and CD7 are expressed on the cell surface. These cells typically do not express the T-cell–specific CD3 complex, but activated NK cells and fetal NK cells express the CD3ϵ chain. Natural killer cells develop in the bone marrow and are thought to arise from the same precursor cells that give rise to T cells.1
Quiz Case 2. Arch Otolaryngol Head Neck Surg. 2000;126(11):1390–1393. doi:
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