Cytotoxicity of parental or IL-2 gene–transduced NK cells against human gastric carcinoma targets in 4-hour⁵¹Cr-release, 1-hour ³H-TdR-release, and 24-hour MTT assays was tested. One representative experiment of 3 performed is shown. *P < .05. (A) NK-92 cells, (B) YT cells.