In contrast to the tumors induced by PyMT in the elastase-tva; Ink4a/Arf-null model of Lewis et al. [7], these acinar cell carcinomas in Pdx1-tTA; tet-o-PyMT-IRES-Luc mice completely lacked endocrine differentiation by immunohistochemistry. The gene discussed is PDX1; the disease is acinar cell carcinoma.