SDC1 and infection: Since wounding of mucosal or skin epidermis results in upregulation of syndecan-1, a HPV-16 receptor candidate [17],[45],[46], and in filopodia formation of the basal keratinocytes that it is essential for reepitheliasation [47], HPV-16 could use actin retrograde flow for efficient transport towards entry sites on the cell body and thus facilitate infection.