Exon 36 was replaced with one that carried a nucleotide substitution of adenosine for guanine at position 4595 (c.4595G>A) resulting in the amino acid substitution of tyrosine for cystein at position 1532 (C1532Y). A floxed neo cassette was also inserted downstream of exon 36. The reduction of protein expression was confirmed by western blot analysis on fibroblast conditioned culture medium extracts. The presence of the neo cassette downregulates gene activity to a greater extent than in Hspg2tm1.1Soni mice as determined by QRT-PCR.