“…These results, and especially the enhanced activity of NK cells that are known to be involved in the killing of tumor cells, are in agreement with previous work showing that postnatal stress can enhance tumor resistance in adulthood (Ader & Friedman, 1965;Dechambre & La Barba, 1978;Levine, 1962;Newton et al, 1962). On the other hand, the increase in T-lymphocyte reactivity appears to be in contrast with the depressed T-cell response, assessed by the plaque-forming cell response to sheep blood cells in adult mice following postnatal stress (Michaut et al, 1981;Raymond et al, 1986).…”