Csl, also known as CBF1, RBPJκ, Lag-1 or Suppressor of hairless, is a highly conserved transcription factor of approximately 56kDa. Its gene is mapped at the chromosome 4p15.2 and has 500 amino acids long. Csl is involved in the cell signal of NOTCH1 and regulation of beta-cell development. This transcription factor is responsible for activating downstream genes of the Notch pathway, which is essential for the nervous system development and the hematopoietic system differentiation among others. When Csl is not associated with Notch proteins, it functions as a role of transcriptional repressor. Csl is expressed in all mammalian tissues and its activity has been detected in lymphoid cells and certain transformed B-cell line by DNA-binding activity as a probe. CD3 (Cluster of differentiation 3), originally known as T3, is one of the first groups of human T lymphocyte surface antigens recognized by monoclonal antibodies. It has been reported that antibodies against CD3 could either stimulate T cells to divide or inhibit the progress of effector functions according to the conditions used. It plays an important role in T cell and the CD3 T-cell co-receptor helps to activate the cytotoxic T-Cell and T helper cells. The CD3 molecule is composed of a protein complex and consists of four distinct chains. The complex of mammals contains a CD3γ chain, a CD3δ chain, and two CD3ε chains. All these chains associate with T-cell receptor and the ζ-chain to generate an activation signal in T lymphocytes.