Tnf^tm2Gkl

69 bp encompassing the AU-rich elements (ARE) were deleted by homologous recombination of a floxed neo cassette and subsequent in vitro cre mediated excision. The resultant allele contained a single loxP site in place of the ARE sequence. ELISA of homozygous mutant mice showed protein levels higher than in wild-type mice, indicating a suppressive role of the AREs. (J:54056)