The document discusses how half of children with HIV die before their second birthday because they do not receive proper treatment. If HIV-positive babies are treated in their first 12 weeks, child mortality decreases by 75%. It also discusses how cancer cells acquire the ability to metastasize by breaking contacts with other cells and the extracellular matrix through integrins and metalloproteases. Angiogenesis is required for tumor growth, and a balance between pro- and anti-angiogenic factors determines whether tumors proliferate or become necrotic.