This application requests support for the 1987 Gordon Conference on Animal Cells and Viruses to be held June 15-19 at the Tilton School, Tilton, New Hampshire.  This meeting, now in its twenty- first year, will emphasize recent work in many areas of the molecular biology of animal viruses, including high resolution structure, pathogenesis, viral oncogenesis, replication of viral genomes, reverse transcription and integration, regulation of transcription and translations, virus assembly and disassembly, host receptors, and the use of viruses as vectors and probes of differentiation.