An adapter protein which plays a role in the regulation of immunoreceptor signaling, including PLC-gamma-mediated B-cell antigen receptor (BCR) signaling and FC-epsilon R1-mediated mast cell degranulation (PubMed:10562326, PubMed:10744659, PubMed:11509653, PubMed:12681493). Together with FGR, it acts as a negative regulator of natural killer cell-activating receptors and inhibits interferon-gamma production (PubMed:15199160, PubMed:16439675). Acts as a positive regulator of both T-cell receptor and natural killer T (NKT) cell receptor signaling in CD4-positive NKT cells (PubMed:16439675). Together with MAP4K1, it enhances CD3-triggered activation of T-cells and subsequent IL2 production (PubMed:11509653). May be involved in tumor necrosis factor induced cell death by promoting reactive oxidative species generation, and MLKL oligomerization, ultimately leading to necrosis (PubMed:26009488). Involved in phosphorylation of LAT (PubMed:11463797). May be involved in high affinity immunoglobulin epsilon receptor signaling in mast cells (PubMed:12681493). When phosphorylated, interacts with PLCG1, PLCG2, GRB2, VAV and LAT (PubMed:10744659, PubMed:11463797). Associated with a tyrosine-phosphorylated polypeptide (p92) in response to immunoreceptor stimulation (PubMed:10562326). Interacts with LBR and AGO2 (PubMed:26009488). Interacts with FGR (PubMed:16439675). Part of a complex consisting of CLNK, SKAP1 and FYB1 (PubMed:12681493). Interacts (via SH2 domain) with FYB1; this interaction allows SKAP1 and FYB1 to promote tyrosine phosphorylation of CLNK by LYN (PubMed:26009488). Interacts (via SH2 domain) with MAP4K1 (PubMed:11509653). Expressed in T-cells, mast cells, natural killer and natural killer T cells (at protein level) (PubMed:10744659, PubMed:15199160, PubMed:16439675, PubMed:11509653). Expressed in cytokine-stimulated hemopoietic cells (PubMed:10562326). By cytokines such as IL2 and IL3 (PubMed:10562326, PubMed:15199160, PubMed:16439675). In natural killer T cells, by alpha-galactoceramide (PubMed:16439675). The N-terminal proline-rich region interacts with the SH3 domain of PLCG1. The SH2 domain is important for restoration of BCR-induced calcium response and JNK2 activation in BLNK-deficient DT40 cells expressing LAT. Tyrosine-phosphorylated upon BCR cross-linking (PubMed:10744659, PubMed:11463797). Tyrosine phosphorylation at both Tyr-69 and Tyr-96 are required for BCR-induced calcium response and are essential to restore PLCG2-mediated signaling in BLNK-deficient DT40 cells, but this phosphorylation is dispensable in cells expressing LAT (PubMed:10744659, PubMed:11463797). Interacts with the SH2 domain of PLCG1 via phosphorylated Tyr-96 (PubMed:10744659, PubMed:11463797). Tyrosine phosphorylation is increased when complexed with SKAP1 and FYB1 (PubMed:12681493). No visible phenotype.