BeiGene (Beijing) Co., Ltd. 1 article published in JoVE Cancer Research A Human Peripheral Blood Mononuclear Cell (PBMC) Engrafted Humanized Xenograft Model for Translational Immuno-oncology (I-O) Research Zhuo Li*1, Xiao Yang*1, Yilu Zhang1, Xiaolong Yang1, Xinxin Cui1, Yanjuan Zhang1, Wenfeng Gong1, Huichen Bai1, Ning Liu1, Zhiyu Tang1, Mingming Guo1, Kang Li1, Tong Zhang1, Lai Wang1, Xiaomin Song1 1BeiGene (Beijing) Co., Ltd. We describe a human peripheral blood mononuclear cell (PBMC) — based humanized xenograft mouse model for translational immuno-oncology research. This protocol could serve as a general guideline for establishing and characterizing similar models for I-O therapy assessment.