Immune checkpoint inhibitors targeting the PD-1/PD-L1 axis have transformed cancer treatment, yielding durable responses in some patients. However, both primary and acquired resistance remain major obstacles, limiting therapeutic benefit in many patients. Understanding the mechanisms underlying anti-PD-1 resistance and developing effective counterstrategies require robust, translational preclinical models. To this end, GemPharmatech has established three distinct models of anti-PD-1 resistance. These models provide a powerful platform to investigate mechanisms of immune escape and evaluate novel therapeutic strategies. They are thus indispensable for unraveling the molecular and cellular basis of treatment failure and for guiding the development of next-generation immunotherapies.