To understand the role of NOTCH1 and its negative regulator NUMB in cervical cancer, we investigated the expression and localization of NOTCH1 and NUMB in samples from 144 patients with cervical intraepithelial neoplasia (CIN) and ICC obtained from the Instituto Nacional de Cancerología-México from 2004 to 2017 using immunohistochemistry and determined their role as predictors of malignancy in ICC. Here, NUMB is linked to cervical squamous intraepithelial neoplasia.