Somatic oncogenic mutations, benign skin lesions and cancer progression: where to look next?

Somatic oncogenic activating mutations in FGFR3 and/or PIK3CA have recently been described in benign epithelial cutaneous lesions that never progress to malignancy (seborrheic keratoses and epidermal nevi). The same mutations have been observed in malignant neoplasms from other tissues (bladder carcinoma, cervix cancer, colorectal cancer, myeloma). However, many of the abovementioned epithelial benign cutaneous tumors do not harbour mutations in FGFR3 or PIK3CA. In this review, we focus on new candidate genes for discovery and we outline the potential of the skin as a model to achieve a better understanding of cancer biology.