“…We have reported previously that human carcinomas spontaneously express abundant IL-2Rb, IL-2Rg and very little IL-2Ra on the cell surface, contain mRNA for these receptor chains, and are inhibited in growth by high molar concentrations of exogenously-delivered IL-2 in vitro and in vivo, in a xenograft model of tumor growth in nude mice (Rabinowich et al, 1992;Weidmann et al, 1992;Yasumura et al, 1994;Lin et al, 1995). Others have reported expression of IL-2Ra-and b-chains on a variety of normal and malignant cells, including human embryonic Âźbroblasts , melanoma cells (Rimoldi et al, 1993), pituitary cells (Artz et al, 1992), or intestinal epithelial cells (Ciacci et al, 1993).…”