EGFR and severe combined immunodeficiency: To investigate whether EGFR inhibition affects in vivo angiogenesis and in turn MM development, we used a MM mouse model in which non-obese diabetic mice with severe combined immunodeficiency (NOD/SCID) were subcutaneously injected with RPMI 8226 cells; after tumors appeared, the animals were treated with either the EGFR inhibitor erlotinib or vehicle until day 40.