Immunization with E.G7 cells induces OVA-specific CTLs but does not protect against E.G7 tumor growth. (A) C57BL/6 mice were immunized with irradiated E.G7 or EL4 cells. Seven days later, spleens of immunized mice were stimulated in vitro with ova257-264 or irradiated EL4 cells for 5 days. Lytic activity against E.G7 and EL4 was measured by ⁵¹Cr release assay. (B) C57BL/6 mice were immunized with irradiated E.G7 cells, EL4 cells or buffer. One week later they were challenged with live E.G7 or EL4 cells s.c. and tumor growth was measured. Each line denotes the kinetics of tumor growth in a single mouse.