We next mutated the C-terminal part of the p53 gene in two rounds of PCR mutagenesis, first with primers 5′-GGGCCTGACTCAGACGGATCCCCTCTGCATCCCGTC-3′ and 5′-GACGGGATGCAGAGGGGATCCGTCTGAGTCAGGCCC-3′, which removed the stop codon and introduced a BamHI site, then with primers 5′-GACGGATCCCCTCTGAATTCCGTCCCCATCACCA-3′ and 5′-TGGTGATGGGGACGGAATACAGAGGGGATCCGTC-3′, which introduced an EcoRI site.