TMPO and heart disorder: Our results show that LAP2 expression is finely regulated upon cardiac differentiation <i>in vitro</i> and is dependent on age and heart compartment <i>in vivo.</i> They contribute to clarifying the potential impact of genetic LAP2a defects and their connection with heart disease, possibly including reduced cardiomyoblast proliferation, increased cardiomyocyte differentiation and altered nuclear envelope remodelling.