Many viruses modulate the host cell cycle to establish optimal conditions for their replication. Several viral proteins have been reported to target the APC, possibly to force the cell into an S phaselike biochemical environment to promote efficient viral replication. Proteins from adenovirus, chicken anemia virus, human papillomavirus, human T-lymphotropic virus, hepatitis B virus, parapoxvirus, and HCMV have been reported to regulate the function of the APC [17] [18] [19] [20] [21] [22] [23] [24] . However, the mechanisms used by these viruses during infection to subvert the APC are largely unknown.