The construct resulting from Cre-loxP mediated recombination was named SypDTA. To confirm that DTA expression driven by Syp promoter could be detected after Cre-loxP mediated recombination in mouse cells, reverse transcriptase PCR (RT-PCR) was performed with different constructs transfected into PCN1 and PCN3 after Adenovirus-Cre (Ad-Cre) infection. Here, SYP is linked to infection.