Fig A2.

Immunohistochemistry images for ErbB family proteins: Representative images from (A) HER2, (B) EGFR, and (C) ERBB3 are shown, with individual patients labeled. For HER2 and EGFR, the cases shown were selected to show the observed range across the cohort, which included samples with completely negative staining to some with marked overexpression. Patient 12, for example, was selected to demonstrate negative EGFR staining. Two images for patient 4 (HER2 staining) are shown side by side to demonstrate focality of staining. For patient 8, the histology of the tumor was mixed urothelial carcinoma (50%) and small-cell carcinoma (50%). Whereas the urothelial carcinoma component stained negative for ERBB3, the small-cell carcinoma component stained 2+ to 3+.