IFN-γ production and cytotoxic activity of HM1.24-specific CTLs from patients with MM. HM1.24-126–specific CTLs (A) and HM1.24-165–specific CTLs (B) were generated from patient no. 2 (HLA-A2⁺, A24⁺) and patient no. 5 (HLA-A2^-, A24⁺), respectively. CTLs (1 × 10⁴ cells) were cultured with target cell lines (1 × 10⁴ cells) for 24 hours and IFN-γ production was measured by ELISPOT assay. (C) HM1.24-126–specific CTLs (1 × 10⁴ cells) from patient no. 3 (HLA-A2⁺, A24^-) were cultured with 2 primary MM cells (patients no. 1 and 2) and several target cell lines (1 × 10⁴ cells) for 24 hours and cytotoxic activity of CTLs was evaluated by granzyme B ELISPOT assay. Values indicate the mean ± SD of triplicate experiments.