Papillomaviruses and their involvement in oncogenesis.

Papillomaviruses have been identified as the causative agents of benign epithelial proliferation in many animals including man. Recent evidence has shown that each viral type will only infect a specific species and tissue. Furthermore, certain papillomavirus types have been found associated with lesions capable of malignant conversion, particularly in response to secondary physical or chemical factors. Many advances have been made in identifying particular papillomavirus types inducing papillomas capable of progression and in the identification of the virally encoded functions involved in viral replication and cellular transformation.