Docking protein that plays a role in tyrosine kinase-based signaling related to cell adhesion and cell spreading. Regulates PTK2/FAK1 activity, focal adhesion integrity, and cell spreading (By similarity). Interacts (via SH3 domain) with PTK2/FAK1 (via C-terminus). The SH3 domain interacts with the C-terminal region of PTK2/FAK1. Phosphorylated on tyrosines by SRC. Belongs to the CAS family.