Exon 41 was replaced with a floxed modified exon 41 with nucleotide substitutions (GAC to TCC) that result in the amino acid substitution of serine for aspartic acid at position 1994 (D1994S). An FRT-flanked neo cassette inserted downstream of the modified exon 41 was removed by flp-mediated recombination. The predicted protein is kinase dead. (J:176679)