To accelerate our endeavors to overcome cancer, Chinese Journal of Cancer has launched a program of publishing 150 most important questions in cancer research and clinical oncology. In this article, 6 more questions are presented as followed. Question 25: Does imprinting of immune responses to infections early in life predict future risk of childhood and adult cancers? Question 26: How to induce homogeneous tumor antigen expression in a heterogeneous tumor mass to enhance the efficacy of cancer immunotherapy? Question 27: Could we enhance the therapeutic effects of immunotherapy by targeting multiple tumor antigens simultaneously or sequentially? Question 28: Can immunotargeting to cytokines halt cancer metastasis? Question 29: How can we dynamically and less-invasively monitor the activity of CD8~+ T killer cells at tumor sites and draining lymph nodes? Question 30: How can the immune system destroy the niches for cancer initiation?