In specific cell types like keratinocytes, Notch signaling plays an important pro-differentiation and tumor suppressing function [3], [33], which is associated with specific down-modulation of the Notch1 gene in keratinocyte-derived cutaneous squamous cell carcinomas (SCCs) [9] and basal cell carcinomas (BCCs) [10], as well as in late stage cervical carcinomas, another important form of keratinocyte-derived tumors [11], [14]. This evidence concerns the gene NOTCH1 and cutaneous squamous cell carcinoma.