Could be a T-cell-specific adapter protein involved in the control of T-cell activation. May play a role in the CD4-p56-LCK- dependent signal transduction pathway. Could also play an important role in normal and pathological angiogenesis. Could be an adapter protein that facilitates and regulates interaction of KDR with effector proteins important to endothelial cell survival and proliferation. This is the function of SH2D2A (SH2 domain containing 2A, Ensembl gene identifier ENSG00000027869).