The long-term objective is to avoid an interruption and to facilitate a continuum of the unbridled exchange of new ideas that was initiated at the First Gordon Research Conference on Prolactin in 1981. The second such conference was held in 1983. This proposal aims specifically toward the granting of funds for travel, subsistence, and registration fees for the scientists who will make up the program for the Third Gordon Research Conference on Prolactin slated for February 3-7, 1986 in Oxnard, CA. In order to carry on a tradition of excellence, speakers and discussion leaders for the Third Conference have been carefully chosen on the basis of their recent discoveries which put them at the cutting edge of prolactin research. Prolactin is both a pluritrophic and a pleiotrophic hormone, i.e. it not only has many targets but often many actions within a target. It regulates, or participates in the regulation of, more diverse functions, in more species, both mammalian, including man, and non-mammalian than any other hormone. Prolactin, therefore, is of great interest to biologists of all kinds: physiologists, biochemists, anatomists, cell and molecular biologists, pharmacologists and clinicians. Basic research has already lead to improvements in the human condition in areas such as infertility and in the medical management, as an alternative to surgical treatment, of pituitary adenomata. The promise for the future ranges from the alleviation of psychiatric disorder to manipulation of the immune system.