The transgene insert comprises 4655 bp of endothelial-cell-specific Mef2c enhancer containing sequence (chr13:83718998-83723651 (GRCm39) consisting of the first coding Mef2c exon and parts of introns flanking it), mouse Hsp68 minimal promoter and ~113 bp of 5' UTR, and the beta-galactosidase reporter gene. (J:94636)