CD3 is a component of T cell surface receptor (TCR), it cantains 5 invariable chains: gamma- , delta-, epsilon-, and zeta/eta.Clevers et al. (1988) showed the TCR/CD3 complex consists of either a TCR alpha/beta or TCR gamma/delta heterodimer coexpressed at the cell surface with the invariant subunits,CD3 is responsible for the signal transduction of the TCR.Synonyms: CD3 zeta chain, T-cell receptor T3 zeta chain, T-cell surface glycoprotein CD3 zeta chain, T3Z, TCRZ