Significant association between deletion and methylation of SLIT2 and ROBO1 in CIN, ROBO1 and ROBO2 in CACX and marginal significance of SLIT2 in CACX were in concordance with Knudson’s modified two-hit hypothesis for candidate TSGs (Table S4). This evidence concerns the gene ROBO1 and cervical squamous intraepithelial neoplasia.