The LAPs of TGF beta-1 and TGF beta-3 contain RGD sequences near the carboxyl termini that are bound by RGD binding integrins. The TGF beta-1 form of LAP (LAP1) binds the integrins alphaVBeta1 (Munger et al. 1998), alphaVBeta3 (Ludbrook et al. 2003), alphaVBeta5 (Munger et al. 1998), alphaVBeta6 (Munger et al. 1999, Araya et al. 2006), alphaVBeta8 (Mu et al. 2002, Araya et al. 2006) and alpha8Beta1 (Lu et al. 2002). Binding to integrins alphaVBeta6 and alphaVBeta8 leads to TGF beta activation.