CD4 and cardiac hypertrophy: For example, whereas CD1d-positive natural killer cells seem to promote the development of neointima after vascular injury in a carotid collar model [54], CD4+CD25+ regulatory T cells adoptive transfer not only reduces angiotensin-induced early infiltration of inflammatory cells in cardiac tissue, but also blunts the subsequent development of cardiac hypertrophy, fibrosis formation, and arrhythmogenic potential [55].