ERBB2 and cancer: A study involving 749 patients showed a 91% concordance for HER2 status between microarray and local IHC/FISH assessments48 and 93% in the MINDACT trial.49 Emerging transcriptomic techniques, such as RNA sequencing, accurately classify HER2 status and can assist in guiding treatment decisions, particularly for HER2-targeted therapies.50 Assessing dynamic HER2 expression could help enhance treatment strategies, determine the optimal timing for changing cancer therapies, and identify patients who may qualify for new clinical trials.