Over the last few years many of the difficulties encountered in applying molecular biology techniques to cardiac muscle have been addressed. Although continuous cardiac cell lines are still, as yet, unavailable, progress in embryonic stem cell systems and in our fundamental understanding of the critical steps that lead to cessation of cardiac myocyte cell division suggests that one may soon emerge. The cis-acting promoter elements and transacting factors responsible for cardiac specificity and inducible expression of cardiac genes are being characterized at a rapid pace. Transgenic models of cardiac disease are being generated and new insights are being made towards the goal of gene therapy in the heart. As the repertoire of techniques for transferring DNA into heart cells continues to expand, so the prospect for efficient and long-term expression of exogenous DNA in heart cells improves. The recent rapid rate of progress promises that ideas once fanciful may ultimately be within our reach.