3, Oncotype Dx 4, and Mammaprint 5, etc. However, no RPM has been widely accepted for Stage IV breast cancer patients. The TBCRC 013 study 6 suggested that the 21‐Gene recurrence score has prognostic value in stage IV breast cancer patients. However, there were more clinicopathological features reported to be significantly associated with survival in these patients, such as progesterone receptor (PR) positivity 7, molecular subtype 8, tumor grade 8, and metastatic patterns 9. This evidence concerns the gene PGR and breast cancer.