Horvitz, H(oward) Robert (1947- )

US biologist and geneticist who was awarded the 2002 Nobel Prize for Physiology or Medicine (with South African molecular biologist and geneticist Sydney Brenner and British geneticist John E Sulston) for his work in the field of genetic regulation of development and programmed cell death (apoptosis).

Horvitz characterized key genes involved in the cell death of the nematode worm, Caenorhabditis elegans. Horvitz joined Sydney Brenner's team in 1974 and studied the nematode worm's genes. He discovered and characterised two key genes involved in apoptosis in the worm, which he described in 1986. Horvitz went on to discover how genes interacted in the programmed cell death process and showed that corresponding genes existed in humans. Disruption to the normal apoptosis process is a key mechanism involved in a range of diseases such as cancer and Alzheimer's disease.

Horvitz was professor of biology at the Massachusetts Institute of Technology (MIT) from 1986 until appointed as Investigator at the Howard Hughes Medical Institute at MIT in 1988. He was elected a member of the US National Academy of Sciences in 1991.