OntologiesgoclassesGO:0003200   
JSON document
endocardial cushion to mesenchymal transition involved in heart chamber septation
http://purl.obolibrary.org/obo/GO_0003200

A transition where an endocardial cell loses apical/basolateral polarity, severs intercellular adhesive junctions, degrades basement membrane components and becomes a migratory mesenchymal cell that will contribute to the formation of the heart septum.