Skin deep and deeper: multiple pathways in basal cell carcinogenesis.

This perspective places the report by Villani et al. that appears in this issue of the journal (beginning on page 1222) in the context of recent work showing an intersection between two important developmental pathways implicated in oncogenesis: the hedgehog and insulin-like growth factor (IGF) pathways. Villani et al. define a key role for the IGF regulatory protein Igfbp2 in a genetic model of basal cell carcinogenesis driven by targeted constitutive activation of hedgehog signaling. Placed in the framework of other recently published work, the observations of Villani et al. both raise questions about the cell of origin for basal cell cancers and define additional putative therapeutic and preventive targets for this disease.