The invention provides an integrin alpha-2 binding agent and methods of using an integrin alpha-2 binding agent to, e.g., inhibit proliferation of cancer cells, modulate tumor growth in a subject, inhibiting angiogenesis, or treating a fibrotic disorder. The invention further provides a method of producing an antibody, the method comprising propagating cancer cells in a 3-dimensional matrix； immunizing a mammal with the propagated cancer cells； and isolating an antibody from the immunized mammal. A method of identifying an agent that inhibits cancer cell proliferation also is provided.
