Links T-cell receptor activation signal to phospholipase C-gamma-1, GRB2 and phosphatidylinositol 3-kinase. Binds to the tyrosine-phosphorylated TCR zeta chain via its SH2 domain. Preferentially expressed by lymphoid cell lines. Tyrosine phosphorylated by LCK. Disease susceptibility is associated with variants affecting the gene represented in this entry. Disease susceptibility is associated with variants affecting the gene represented in this entry. Belongs to the SH2B adapter family.