Specific CTL lysis of ⁵¹Cr-labeled host, donor, and third party targets by splenocytes from B10, B10.D2, and two representative chimeras: animal no. 5 transfused with a combination of syngeneic and allogeneic bone marrow cells (68.7% donor-type splenocytes; see also Fig 1) and animal no. 8 transfused with only allogeneic bone marrow cells (95.1% donor-type splenocytes). CTL response was examined 8 months after conditioning. Spontaneous release was less than 25%.