text: hESCs and hiPSCs are the primary cells used to generate hECTs. Human pluripotent stem cells are differentiated into cardiomyocytes (hPSC-CMs) in culture through a milieu containing small-molecule mediators (e.g. cytokines, growth and transcription factors). Transforming hPSC-CMs into hECTs incorporates the use of 3-dimensional (3D) tissue scaffolds to mimic the natural physiological environment of the heart. This 3D scaffold, along with collagen – a major component of the cardiac extracellular matrix – provides the appropriate conditions to promote cardiomyocyte organization, growth and differentiation.