Cardiac fibroblasts (CF) are the principal cell type of the heart. They provide structural support for cardiac myocytes, are a source of paracrine growth factors, and are an important cellular component of the myocardial response to injury. CF are responsible for extracellular matrix synthesis in the heart during development and pathological conditions. Their proliferation and matrix synthesis is essential for scar formation at sites of myocardial infarction or cardiac fibrosis. CF also respond to changes in microenvironments in pathological conditions by modulating integrin expression. Human Cardiac Fibroblasts culture allows to study the cardiac matrix remodeling by physiological (exercise) and pathological (hypertension) stressors. Immortalized Human Cardiac Fibroblasts also allow to stablish in vitro models for HIgh Throughput and High Content Screening.