LSIL does not progress directly to invasive carcinoma, and, in fact, most cases regress spontaneously; only a small percentage progress to HSIL. LSIL represents a productive HPV infection in which there is a high level of viral replication, but only mild alterations in the growth of host cells. For these reasons, LSIL is not treated like a premalignant lesion. LSIL is approximately ten times more common than HSIL