Chapter 11 The Fetal Mouse Heart in Organ Culture: Maintenance of the Differentiated State11This work was supported in part by grants from the Massachusetts and San Diego County affiliates of the American Heart Association and by the NIH Specialized Center of Research on Ischemic Heart Disease HL-17682, HL-22290, and HL-21751. Joanne S. Ingwall is an established investigator of the American Heart Association