1. unchangeable: heredity 2. partially changeable: 1. environmental pollution: social environment, office environment, home environment 2. psychological factors (cancer character): sulking, careful eyes, too competitive 3. infections: hepatitis, Helicobacter pylori, papillomavirus, HIV, Mycobacterium tuberculosis Wu Wan Yin, Department of Oncology, Guangdong Hospital of Traditional Chinese Medicine 3. fully controllable: 1. smoking: first, second and third-hand 2, alcoholism 3, less vegetables, more fat, pickled barbecue fried food 4, unscientific living arrangements: exercise less, stay up late, overwork 5, sexual disorder 6, small habits: drink (eat) overheated food, chewing betel nut, hold two stools