To investigate potential mechanisms of LNP-CTNNB1 + β-PD1 synergy we performed IHC for granzyme B (GZMB) to address cytotoxic T cell activity and observed an overall increase in GZMB+ lymphoid aggregates within and surrounding remnant tumor nodules in LNP-CTNNB1 treated mice receiving β-PD1 compared to IgG treatment (p=0.08) (Figure 7j–k), suggesting improved anti-tumor immunity in mice receiving combination therapy. Here, GZMB is linked to neoplasm.