Exposure to apoptotic cells prior to BMT improves survival. BALB/c mice were injected with C57BL/6 BM plus conventional T cells (Tcon) only (circles) or with prior injection of ECP-treated BALB/c-treated cells (triangles) or with prior injection of BALB/c cells treated with 8MOP but no UV light (squares). See Figure 1A in the article by Florek et al that begins on page 1832.