CD3D/CD3 delta, His, Human

T-cell surface glycoprotein CD3 delta chain, also known as CD3D, is a single-pass type I membrane protein.In immunology, the CD3 (cluster of differentiation 3) T cell co-receptor helps to activate both the cytotoxic T cell (CD8 naive T cells) and also T helper cells (CD4 naive T cells). It consists of a protein complex and is composed of four distinct chains. In mammals, the complex contains a CD3gamma chain, a CD3delta chain, and two CD3epsilon chains.