The antibodies used were the mouse anti-human integrin β1 antibodies TS2/16 (activating; a gift from Francisco Sanchez-Madrid, Universidad Autonoma de Madrid, Spain), 12G10 (activating) (Mould et al., 1995b (link)), and K20 (nonfunction-modulating, Immunotech); rat anti-human integrin β1 antibodies mAb13 (inhibitory) (Akiyama et al., 1989 (link)) and 9EG7 (activating, Pharmingen); rat anti-human integrin α5 mAb16 (inhibitory) (Akiyama et al., 1989 (link)) and mAb11 (nonfunction-modulating) (Miyamoto et al., 1995 (link)); mouse anti-human integrin α5 antibodies SNAKA52 (inhibitory) and JBS5 (inhibitory, Serotec); mouse anti-human integrin αV L230 (inhibitory, ATCC); and polyclonal rabbit anti-human fibronectin Rb745 (Cukierman et al., 2001 (link)).