Gas6 deficiency did not affect donor T-cell proliferation and stimulating capacities of APCs in MLR. WT or Gas6^−/− responder lymphocytes isolated from FVB mice bone marrow were mixed with irradiated (30 Gy) stimulator spleen cells (WT or Gas6^−/−) with a different H-2D locus. Proliferation of responder lymphocytes was measured by a chromogenic substrate after 3 days of culture. Data are mean ± SEM; n = 9. P > .05 (analysis of variance).