IGF1 and squamous cell intraepithelial neoplasia: In quantitative expression analysis of different IGF1 mRNA isoforms in various stages of CC in vivo, overexpression of all of the IGF1 mRNA isoforms (Ea, Eb and Ec) was detected in precancerous lesions (L-SIL, H-SIL) (HPV-positive), as compared to control (HPV-negative) and cervical cancer (HPV-positive).