Cell adhesion leukocyte receptor expressed by mucosal venules, helps to direct lymphocyte traffic into mucosal tissues including the Peyer patches and the intestinal lamina propria. It can bind both the integrin alpha-4/beta-7 and L-selectin, regulating both the passage and retention of leukocytes (By similarity). Homodimer. Detected in Peyer patches and mesenteric lymph nodes but not in spleen.