mRNA cancer vaccines represent a next-generation immunotherapy platform with the potential to elicit robust, antigen specific immune responses. Upon in vivo delivery, mRNA vaccines are taken up by antigen-presenting cells (APCs), translated into the tumor associated antigen and presented via MHC molecules to activate adaptive immunity. However, standard mouse models with murine MHC molecules are not suitable for evaluating these MHC-restricted immune responses. GemPharmatech has developed a series of MHC knock-in (KI) models across multiple mouse backgrounds including immunocompetent mice B6, BALB/c, CB6F1 and immunodeficient NCG derived mice. These models express human HLA molecules, enabling the accurate evaluation of antigen presentation, immunogenicity, and therapeutic efficacy of mRNA vaccines. Our diverse portfolio of MHC knock-in mouse models provide more versatile and translationally relevant platforms for preclinical testing of mRNA-based cancer vaccines and combination immunotherapies. These models bridge the gap between murine and human immune systems, enhancing predictive power in vaccine development pipelines.