The scAAV backbone vector containing human CNP promoter, the coding sequence of fluorescent protein Venus, and the artificial miRNA sequence. The human CNP promoter was a 1.8-kilobase 5′ flanking sequence of the human CNP gene. The engineered miRNA cassette was placed in the 3′ UTR of the Venus sequence and consisted of a 5′ flanking region derived from miR155, a reverse complement of the 21-nucleotide target sequence, a 19-nucleotide loop sequence derived from miR155, nucleotides 1–8 and 11–21 of the sense target sequence, and a 3′ flanking region derived from miR155.