The protein encoded by this gene contains a proline-rich region, a pleckstrin homology (PH) domain, and a region in the carboxy terminal half with similarity to the Src Homology 2 (SH2) domain. This protein is a substrate of tyrosine-protein kinase Tec, and its interaction with tyrosine-protein kinase Tec is phosphorylation-dependent. This protein is thought to participate in a positive feedback loop by upregulating the activity of tyrosine-protein kinase Tec. Variants of this gene have been associated with autosomal-dominant hypercholesterolemia (ADH), which is characterized by elevated low-density lipoprotein cholesterol levels and in increased risk of coronary vascular disease. Alternative splicing results in multiple transcript variants.