The Ventana system will remain the first but probably not the only one approved to identify HER2-low patients, as new evidence has shown that the Dako system detects HER2 expression with higher sensitivity compared to the Ventana system, not only in ISH-positive BC tumors, but also HER2 tumors without gene amplification (IHC 1+/2+), thus adding more patients identified as HER2-low patients and selected for new ADC targeted therapies [72]. Here, ERBB2 is linked to breast cancer.