Human papillomavirus particles, coloured transmission electron micrograph (TEM). Human papillomavirus (HPV) particles (virions) consist of a protein capsid (red) enclosing DNA (deoxyribonucleic acid), the genetic material of the virus. HPV causes warts, which mostly occur on the hands and feet. Certain strains also infect the genitals. Although most warts are non-malignant (not cancerous), some strains of HPV have been associated with cancers, especially cervical cancer.