From: Inter-observer reproducibility of HER2 immunohistochemical assessment and concordance with fluorescent in situhybridization (FISH): pathologist assessment compared to quantitative image analysis
IHC/FISH
Machine 1
Machine 2
Visual 1
Visual 2
FISH
Negative (IHC 0,1+/FISH <1.8)
434
445
415
431
394
Equivocal (IHC 2+/FISH 1.8–2.2)
105
163
52
48
37
Positive (IHC 3+/FISH >2.2)
77
8
149
137
185