EGFR and cancer: We should be able to use EGFR+ and EGFR- cancer cells grown as xenografts in nude mice to directly extend the in vitro data, and expand the work into more clinically relevant patient-derived xenografts (PDX) [37] in severe combined immunodeficient (SCID) mice, which lack B- and T-cell function but retain innate immunity including the complement system [38].