This is an update of a 1991 review on tumor suppressor genes written at a time when understanding of how the genes work was limited. A recent major breakthrough in the understanding of the function of tumor suppressor genes is discussed. (LZ)

Discusses one mechanism proposed for the two-step initiation/promotion scenario of the development of cancer called oncogenes and a possible alternate mechanism that may prevent tumors from developing. Uses the example of retinoblastoma to illustrate the mechanisms. States that these mechanisms may not be caused by the activation of oncogenes. (CW)

Reviews major developments in areas that are at the cutting edge of biological research. Areas include: human anti-cancer gene, recombinant DNA techniques for the detection of Huntington disease carriers, and marine biology. (CW)