Table 1.

List of human papillomavirus (HPV) viral proteins and their major functions.

Viral Protein	Protein Functions
E1	Viral DNA replication and transcription
E2	Viral DNA replication, apoptosis, transcription repressor of E6/E7
E4	Viral DNA replication
E5	Immune recognition (major histocompatibility complex, MHC)
E6	p53 degradation, alteration of cell cycle regulation, apoptosis resistance
E7	retinoblastoma (pRb) degradation, re-entry into S phase cell cycle, p16 overexpression
L1	Major viral capsid protein
L2	Minor viral capsid protein