CIK cells induce much less GVHD in a major-mismatched BMT model. Lethally irradiated Balb/c (H-2^d) hosts received BM with either CIK cells or fresh splenocytes at the indicated dose from wild-type FVB (H-2^q) mice. Percent survival (A) and percent body weight change (B) are presented. □ indicates BM (n = 5); ▵, CIK cells 5 × 10⁶ (n = 5); ×, CIK cells 10 × 10⁶ (n = 5); ◇, CIK cells 20 × 10⁶ (n = 5); ▿, fresh splenocytes 2.5 × 10⁶ (n = 5); ■, radiation control (n = 5). Results from one representative experiment are shown.