To better understand the potential roles of PGRMC1 expression in breast cancer, we initially analyzed the ex-pression of PGRMC1 at transcript level in breast cancer patient cohort retrieved from the TCGA-BRCA and METABRIC dataset We found that PGRMC1 was associated with tumor subtypes, patient age, estrogen receptor (ER) status, progesterone receptor (PR) status and Her2 status. Here, ESR1 is linked to breast cancer.