An A-to-G point mutation (c.707A>G) was engineered in exon 7 to change asparagine codon 236 to a serine codon (p.N236S). The loxP site flanked neomycin resistance gene cassette that was inserted into intron 11 was removed through subsequent cre-mediated recombination. The mutation is found in some human tumors and some tumorigenic mouse cell lines. (J:283471)