 Cell-based immunotherapy shows promising cancer treatment and has potential synergy with surgery, chemotherapy, and radiotherapy. Cytokine-induced killer, CIK, cells are a heterogeneous subset of X-vitro-expanded, polyclinal T-effector cells with both natural killer, NK, and T-cell properties that present potent non-major histocompati complex restricted cytotoxicity against tumor-target cells. Initial clinical studies on CIK cell therapy have provided encouraging results, but issues such as inadequate quality control and quantity of CIK cells as well as exaggerated propaganda led to the Ministry of Health in China stopping CIK cell therapy in May 2016. To overcome these challenges, it is important to develop a standardized operation procedure, SOP, and system for evaluating anti-tumor efficacy in a safe way. This article was authored by Yiming Meng, Jifu Yu, Yifeng Wu, and others.