We performed tumor-immune profiling of the two models to identify the potential mechanism for anti-PD-1 response. In order to delineate the mechanisms of anti-tumor activity of ICB in preclinical syngeneic tumor models, we selected two syngeneic murine colorectal cancer models based on in vivo screening for sensitivity with anti-PD-1 therapy. Harnessing preclinical tumor models is one way to understand the mechanism of treatment response. Despite many preclinical and clinical studies to understand the mechanism of anti-tumor efficacy of ICB, the mechanism is not completely understood. However, anti-tumor response of the ICB is insufficient for many patients and limited to specific tumor types. Immune checkpoint blockade (ICB) therapies have changed the paradigm of cancer therapies.