B1 - VLA family - found on many cells, binds extracellular matrix and allows for migration through extracellular matrix
B2 - (3 kinds) 1. LFA-1 (CD11a/CD18), expressed by most leukocytes - binds ICAM 1,2,3 of endothelium. 2. CR3 (CD18/CD11b) - on phagocytes. Binds ICAM-1 and C3b so, binds to endothelim and is a opsonin receptor. CR4 (CD18/CD11c) on phagocytes, bind iC3b opsinin -> phagocytosis.