CD81 and cytomegalovirus infection: A weak inhibitory effect was also reported using a recombinant protein LEL-GST EC2 of CD63, CD151, CD81 and CD9 against human papillomavirus (HPV) (16) on the immortalised human epithelial cells (HeLa) and immortalised human keratinocytes (HaCaT), while no significant reduction was observed in human cytomegalovirus (HCMV) infections using human umbilical vein endothelial cells (EA.hy926) (16).