Compositions and methods for inducing PD-L1 internalization are disclosed. The methods include reducing the amount of cell surface PD-L1 by contacting a cell expressing PD-L1 with a compound that binds to cell surface PD-L1 and induces PD-L1 internalization. Compounds that induce PD-L1 internalization can be used to enhance, stimulate and/or increase an immune response and treat a PD-1-related disease or condition.
