HER2/Neu Copy Number Ratio Less than 2 by FISH

**Semantic type:** Laboratory or Test Result

**Definition:** An indication that the ratio for a HER2/Neu probe to a chromosome 17 probe detected in a sample using fluorescence in situ hybridization (FISH) is less than 2.

**Synonyms:** - ERBB2 Copy Number Ratio Less than 2 by FISH - HER2 Copy Number Ratio Less than 2 by FISH - HER2/Neu by FISH Ratio <2 - HER2/Neu by FISH Ratio Less than 2