On the nature and function of human uterine granular lymphocytes

The 'foetal allograft' concept of the maternal-foetal relationship is currently being questioned. This is partly due to the increasing awareness of uterine large granular lymphocytes, a subset of natural killer cells found in the human endometrium at the time of placentation. Analogous cells are present in several species. The possible role of these cells in the regulation of the trophoblast-maternal interface is discussed here by Ashley King and Yung Wai Loke.