Probable adapter protein involved in signaling pathways. Interacts with the SH2 and SH3 domains of various signaling proteins when it is phosphorylated. May promote FYN activation, possibly by disrupting intramolecular SH3-dependent interactions (By similarity). Interacts with FYN, GRB2 and PIK3R1 when phosphorylated. Interacts with LYN. A small proportion is membrane-associated. Phosphorylated on tyrosines by FYN and LYN. Belongs to the TOM1 family.