Cumulus cell is a specialized granulosa cell that surrounds and nourishes the oocyte. This cell-type surrounds the fully-grown oocyte to form a cumulus-oocyte complex (abbr. COC). The terms cumulus oophorus cells, cumulus granulosa cells, cumulus oophorous granulosa cells, granulosa-cumulus cells are used to make a distinction between this cell and the other functionally different subpopulation of granulosa cells at the wall of the Graafian follicle. [ http://www.copewithcytokines.org/cope.cgi?key=cumulus%20cells GOC:tfm ]