Ptf1a is expressed in the pancreatic acinar cell lineage and also in a poorly-defined (putative multipotent) pancreatic progenitor population that gives rise to endocrine, acinar and duct population. By expressing tamoxifen-inducible Cre recombinase from the endogenous Ptf1a locus, lineage-tracing experiments can determine at what developmental stage Ptf1a expression becomes restricted to the acinar cell lineage with a better understanding of the spatiotemporal distribution and developmental potential of the Ptf1a-expressing cells. These mice will also be a useful tool for selectively targeting recombinase activity to the pancreatic acinar cell lineage or early pancreatic progenitors for the conditional deletion or ectopic activation of genes of interest.