ERBB2 and breast cancer: In order to test this hypothesis, in this study, we aimed to explore the clinicopathological features, survival rates, and HER2 amplicon mRNA expression of Colombian women affected with HER2-low breast cancer compared to HER2-negative (0+) and HER2-positive groups (2+ with ISH+ or 3+), with the expectation that it will lead to a better understanding of this disease clinical features in the Colombian population.