A previous study showed a transient downregulation of PAP/Reg3β [32] and our current results confirm this result and extend it to Reg3α and Reg3γ. There is a significant decrease in mRNAs for these genes at very early times after caerulein injection in both wild type and CF mice, followed by recovery and overexpression at later times as the tissue recovers from pancreatitis. This evidence concerns the gene REG3G and cystic fibrosis.