Figure 1

Initial criteria for ERBB2 determination of immunohistochemistry scores (0/1+/2+/3+) (a); photomicrography of typical ERBB2 protein expression (VENTANA 4B5 and HercepTest) (b); and ERBB2 gene amplification (fluorescent (FISH) or silver in situ hybridization (SISH)) (c) in colorectal cancer archival samples.