Comparative expression of selected genes in transgenic and wild-type lungs and different endodermal organs. (a,b) Comparison of gene expression between wild-type and transgenic lungs by RT-PCR. (a) CatCLef1 (transgenic fusion gene), aquaporin 5 (type I cell marker), SftpA and SftpB (both type-II-cell markers), while SftpC is also expressed in lung progenitor cells; β-actin is the control. (b) Sox9 is normally expressed in distal lung endoderm; Cdx1 is a Hox gene expressed in duodenum and intestine; Atoh1, Delta-like 3 (Dll3) and and growth factor independent 1 (Gfi1) are expressed in intestine; defensin-related cryptdin 6 (Defcr6, also known as cryptdin6) and matrix metalloproteinase 7 (MMP7) are Paneth cell markers; trefoil factor 3 (Tff3) is a goblet cell marker; Demilune cell and parotid protein (Dcpp) is a tracheal submucosal gland marker; Reg4 is an intestinal epithelial marker; small proline rich protein (Sprr2A) is expressed in the stomach, duodenum, and intestine. (c) Expression of selected genes in adult organs.