The transgene was designed with (from 5' to 3') the CAG promoter (containing a CMV-IE enhancer/beta-actin promoter), a loxP-flanked enhanced green fluorescent protein (EGFP) and polyA signal, a hemagglutinin (HA)-tagged porcine transforming growth factor, beta 1 (Tgfb1) cDNA, and a 2x-polyA signal. The Tgfb1 cDNA was modified to be constitutively active by missense mutations of two cysteine residues (C223 and C225) to serines. Line C8 was generated. (J:158613)