To investigate the expression level of ECM1 in ER+ breast cancers, we analyzed the transcriptome data from The Cancer Genome Atlas (TCGA) (Ciriello et al. 2015) and METABRIC (Curtis et al. 2012) breast cancers by subtypes classified by PAM50 (Parker et al. 2009). The gene discussed is ECM1; the disease is breast carcinoma.