Mig pretreatment protects lin⁻ cells from chemotherapy in CFU-S assays. Donor lin⁻ cells were isolated and treated with Ara-C and then transplanted into irradiated recipient mice. Mig group cells were preincubated with the 300 ng/mL recombinant Mig protein. Before incubation with Ara-C, control cells were supplemented with equal volumes of PBS. (A) Eleven days after transplantation, mice from both groups were killed, and CFU-spleen numbers were counted. In the Mig group (n = 13), significantly higher CFU-spleen numbers were observed than in the PBS group (n = 8; **P = .002). (B) Mice injected with Mig-treated cells showed higher survival rates (*P = .039). Data are representative of 3 independent experiments (n = 7-16).