Arnheim et al.[25] did not find any single gene to be associated with CIN but found that a genotype comprising only KIR2DL1, KIR2DL2, KIR2DL3, KIR2DL4, KIR3DL1, KIR3DL2, KIR3DL3 and KIR2DS4 was associated with an increased risk of developing CIN. This evidence concerns the gene KIR2DL4 and cervical squamous intraepithelial neoplasia.