A subpart of the chicken second heart field (SHF) NK2 homeobox 5 enhancer (cardiac activating region 3 (CAR3); nucleotides 976-3047 after transcriptional start site) was used to drive the expression of a reporter gene cassette containing the hsp68 promoter, lacZ beta-galactosidase gene and poly(A) signal sequences. (J:326594)