Integrin alpha-1/beta-1 is a receptor for laminin and collagen. It recognizes the proline-hydroxylated sequence G-F-P-G-E-R in collagen. Involved in anchorage-dependent, negative regulation of EGF-stimulated cell growth (By similarity). Heterodimer of an alpha and a beta subunit. Alpha-1 associates with beta-1 (By similarity). Interacts with RAB21 (By similarity). Interacts (via cytoplasmic domain) with PTPN2; activates PTPN2 phosphatase activity towards EGFR and negatively regulates EGF signaling (By similarity). The integrin I-domain (insert) is a VWFA domain. Integrins with I-domains do not undergo protease cleavage. Belongs to the integrin alpha chain family.