The 150 most important questions in cancer research and clinical oncology series: questions 40-49.

Since the beginning of 2017, Chinese Journal of Cancer has published a series of important questions in cancer research and clinical oncology, which sparkle diverse thoughts, interesting communications, and potential collaborations among researchers all over the world. In this article, 10 more questions are presented as followed. Question 40. Why do mice being used as tumorigenesis models raised in different places or different conditions possess different tumor formation rate? Question 41. How could we generate more effective anti-metastasis drugs? Question 42. What is the molecular mechanism underlying heterogeneity of cancer cachexia in patients with the same pathologic type? Question 43. Will patients with oligo-metastatic disease be curable by immunotherapy plus stereotactic body radiotherapy? Question 44. Can the Warburg effect regulation be targeted for cancer treatment? Question 45. Why do adenocarcinomas seldom occur in the small intestine? Question 46. Is Epstein-Barr virus infection a causal factor for nasal natural killer/T cell lymphoma formation? Question 47. Why will not all but very few human papillomavirus-infected patients eventually develop cervical cancer? Question 48. Why do cervical carcinomas induced by human papilloma virus have a low mutation rate in tumor suppressor genes? Question 49. Can viral infection trigger lung cancer relapse?