Fig. 2.

Representative images of immunostaining for three molecular biomarkers. a–g The RGB images acquired by RGB imaging system. b–h The corresponding MS images acquired by MSI system. a, b Positive HER2 membrane staining was scored as 2+. c, d Positive HER2 membrane staining was scored as 3+. e, f CK5/6 staining mainly in the cytoplasm; this tumor was classified as CK5/6-positive. g, h ER staining in the nucleus, this tumor was scored as ER-positive. The magnification of all figures is ×400. Scale bar: 20 μm for all images