In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

Here we demonstrate that the T cell antigen receptor zeta - chain - associated ZAP - 70 kinase and T cell antigen receptor zeta - chain immunoreceptor tyrosine - based activation motifs are essential for the membrane recruitment of SOS and Vav .
ZAP - 70