Figure A2.

Illustration of the E/M score computation steps adapted for patient-derived xenograft model. Registered images (from the same tissue slide) processed at 10× magnification (0.906 µm-side pixel): (a) human-specific VIM expression; (b) standard double IHC step for evidencing pan-CK expression (red staining) and Ku80 (nuclear marker for identifying human cells in animal model, brown staining); (c,d) detection of VIM+ (red) and pan-CK+ (green) areas, and human cell nuclei (blue); (e) detection of pan-CK+/VIM+ area (yellow), pan-CK+/VIM− area (green), and pan-CK−/VIM+ area (red). The hybrid E/M score is computed as the ratio between the yellow area and the sum of the yellow and green areas. This methodology was recently applied in a study submitted for publication.