GZMB and neoplasm: Employing Tbx21-floxed (Tbx21fl/fl) mice to Gzmb-Cre mice to create Tbx21fl/fl;Gzmb-Cre (Tbx21−/−) mice, Tbx21 knockout significantly suppressed the proportion of lung tumor-reactive Teff cells in the spleen on day 7 post-tumor cell inoculation in both KP.SIY models (Fig. 5e, f).