Definition Human Papillomaviruses (HPVs) are a group of DNA viruses, which have a remarkable target cell specificity: they have been reported principally in anogenital tract, urethra, skin, larynx, tracheobronchial mucosa and oral cavity. More than 100 different types of HPV have been classified and they are divided into high (e.g. 16,18, 31) and low oncogenic risk genotypes (e.g. 11, 42, 36), ...