A single loxP site remained in place of a genomic fragment encompassing the promoter and exon 1 after cre-mediated excision of loxP sites inserted by homologus recombination. The start codon is contained within exon 2 and though neither transcript nor protein was detected in renal tissue via Northern or Western blot analysis, low levels of normal sized transcript and protein were detected in sciatic nerve. (J:89888)