The dermis, the skin's next layer, is a thick layer of fibrous and elastic tissue (made mostly of collagen, with a small but important component of elastin) that gives the skin its flexibility and strength. The dermis contains nerve endings, sweat glands and oil (sebaceous) glands, hair follicles, and blood vessels.
âAll cancers are caused by genetic mutations, and in some cases we know the processes driving them, for example, tobacco smoking in lung cancer, however, our understanding of the causes of mutation in most cancers is remarkably limited,â Grimmond says.
Exposure to pollutants such as metals, dust, chemicals, or pesticides can increase the risk of cancer. At least four types of DNA viruses, hepatitis B and C viruses, Epstein-Barr virus, and human papillomavirus, are directly believed to cause human cancers. Nutrition is emerging as a way to help prevent cancer.