For instance, recently, the FDA expanded the indication of palbociclib in combination with endocrine therapy to men with advanced HR-positive/HER2-negative breast cancer, based on real-world evidence from electronic health records and insurance claims in combination to data from two clinical trials.23 In this setting, the FDA recognises the clinical utility of real-world data and encourages sponsors to add real-world evidence as part of regulatory submissions.24 This evidence concerns the gene ERBB2 and breast cancer.