tokens: Amplification of full - length p53 coding region from SH - SY5Y , IGR - N - 91 , IGR - NB8 and SK - N - BE ( 2 ) cell lines was performed using forward primer at position 152 and reverse primer at position 1583 ( F1 and R7 , respectively , Table 1 ; GenBank accession no . K03199 ) .