(a) PGE2 was measured in conditioned media from cultured murine mammary tumor cell lines 66.1, 410.4, 67, and the murine lymphoma line Yac-1. (b) Conditioned media was collected from NK cells, NK cells treated with vehicle control (EtOH) and COX-inhibitor (indomethacin) for 18 hours and PGE2 levels determined by ELISA assay. (c) Conditioned media was isolated from NK cells and T-NK cells, T-NK cells treated with vehicle control (EtOH) and COX-inhibitor (indomethacin). Results are from triplicate wells. Data reported as mean pg PGE2/mL/1×106 cells ± standard error.