Fig. 4

HER2 positivity in New Mexican cases of gallbladder cancer by immunohistochemistry. The panels (clockwise from top left) represent HER2 staining status of 0, 1+, 3+ and 2+ grades. Gallbladder cancer HER2 staining is axial, similar to the staining pattern seen in gastric cancers. In contrast, HER2 staining in breast cancers is more circumferential and evenly distributed around the tumor cell periphery