Lymphocyte-specific protein tyrosine kinase p56 (Lck) is a member of the Src family of non-receptor protein tyrosine kinase.Lck plays an important role in mediating T-cell receptor (TCR) signal transduction and the development,differentiation,proliferation,and activation of T-cells [1].Lck contains N-terminus of myristylation sequence,a unique aminoterminus region,followed by Src homology 3 (SH3) and SH2 domains and a C-terminus oftyrosine kinase catalytic domain [2].Lck can associate with the inner face of the plasma membrane through its myristoyl glycine and palmitoyl cysteines in the amino-terminus [3].Following the myristylation sequence,there is the unique region,a short region of ～ 80 amino acids.This unique region is involved in the interaction of Lck with specific cellular proteins [4,5].