“…Cells originally identified in the draining lymph nodes, which produce a soluble non-specific immunosuppressive substance (Clark & McDermott, 1978;Clark, McDermott & Szewczuk, 1980), have also been detected in decidual tissue (Clark & McDermott, 1981) and may constitute a proportion of the small round cells observed in the cultures. The nature and rela¬ tionships of these soluble factors to other decidual tissue products (Umapathysivam & Jones, 1978 ;Bell, 1979b;Rosenberg, Maslar & Riddick, 1980;Sutcliffe, Bolton, Sharp, Nicholson & MacKinnon, 1980) is unknown, but appear to be associated with two protein fractions (Badet et al, 1983).…”