17 January 1992
Vol 255, Issue 5042

About The Cover

Model of the complex of human growth hormone and the extracellular domain of its receptor. One hormone molecule (red) is bound to two receptor molecules (blue and green); the pebbled yellow surface represents the cell membrane. The dimerization of the extracellular domains by the hormone is likely to aggregate the intracellular domains of the receptor as well, thereby producing signals leading to cell growth differentiation. See page 306. [Graphics by T. Hynes and A. M. de Vos with MIDAS-plus software]