MYC and carcinoma: This postnatal ChP Nestin-Cre expression has been paired with StopFLMYC mice [62], in which a floxed stop cassette [loxP-stop-loxP] is located between a promoter and the gene of interest [63], the tumor oncogene MYC. Cre-mediated excision of the stop cassette drives human c-MYC overexpression in ChP epithelial cells, resulting in devastating ChP tumors, matching WHO Grade III carcinoma classification used in the clinical setting.