Although the Ptchflox/flox ERT2+/− BCC model is very easy to handle (i.e., application of one single dose of tamoxifen) and is solid with respect to induction of a specific BCC subtype (i.e., 100% of animals develop the nodular subtype 90 days after BCC induction), it also may have some disadvantages. This evidence concerns the gene MAPK3 and skin basal cell carcinoma.