PPIB and cystadenoma: To determine whether the depletion of β-catenin activity can abolish MCN formation in Pdx-1CreLKB1L/L mice, we further produced triple mutant mice (Pdx-1Cre LKB1L/L β-cateninL/L mice) by crossing the mice with a conditional β-catenin allele with Pdx1-Cre LKB1L/L animals which had a well-defined course of cystadenoma initiation and progression.