Hodgkin/Reed Stemberg (HRS) cells mediate the classical features of Hodgkin's disease. However, because of their rarity in tumor tissue, little is known about their origin and function. Recent advances in biotechnology, including the single cell manipulation, enabled the insight into the biology of HRS cell. It has been demonstrated that in the great majority of cases they are of germinal center B cell origin, with highly developed interactive network with adjacent cells via expression of cell adhesion molecules, tumor necrosis factor receptor superfamily, and elaboration of different cytokines.