Occasionally becomes malignant. Sexual promiscuity and changes in hormone balance may be predisposing factors for their development. Laryngial papillomas have been associated with the same virus, and may be transmitted at birth. HPV-7 is known as meat handlers wart. All papilloma viruses have the same organization.
Transcription takes place only on one strand .
In productive infection the whole genome is transcribed. There are about 1000bp involved in regulation located just upstream of E1. This region contains the origin of DNA replication, transcriptional promoters and enhancers. Papilloma transcription is complex because of the presence of multiple promoters, complex and multiple splice patterns and differential production of mRNA species in different cells. Early mRNAs code for viral factors involved in viral plasmid replication, regulation of viral transcription and cellular transformation.