- HER2 gene amplification by FISH/CISH ( > 6 HER2 gene copies per nucleus, or a FISH ratio [HER2 gene copies to chromosome 17 signals] of > than 2.2.) Patients with a negative or equivocal overall result (FISH test ratio of ≤ 2.2, ≤ 6.0 HER2 gene copies per nucleus) and staining scores of 0, 1+, 2+ or 3+ (in 30% or less neoplastic cells) by IHC are not eligible for participation in the trial.