Importin-β, exportin-5, p16, Ki-67, Mcl1, PDL1, and cFLIP are each over-expressed in the majority of CIN 1 lesions. These biomarkers, plus HPV E6/E7 RNA, were analyzed in carcinoma-in-situ (CIS), microinvasive, and squamous cell carcinoma (SCC) of the uterine cervix and cervical carcinoma cell lines. Only p16 and Ki-67 continued to be over-expressed in CIS, with a concomitant marked increase in E6/E7 RNA. There was a highly significant increase in PDL1 expression and decrease in Ki-67 (each p < 0.001) in microinvasive cancer compared to CIS whereas p16 and E6/E7 remained stable. As the lesion progressed to SCC, p16 and E6/E7 RNA remained strongly overexpressed with a concomitant over expression of importin-β and Ki67. HPV positive Caski cells showed significant elevations of p16, importin-β, exportin-5 and PDL1 compared to the HPV negative cervical cancer cell line C33A, consistent with viral induction of these biomarkers. The data suggest that PDL1 may be a useful biomarker to differentiate CIS from microinvasive cancer and, thus, anti-PDL1 therapy may inhibit the progression of CIS to the invasive stage.2020-01-31