Here, we used the public breast cancer gene expression microarray datasets from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) to compare the mRNA expression levels of TGFB1, TGFB2, TGFB3, TGFBR1 and TGFBR2 in primary tumours and tumour-adjacent normal tissues, and to evaluate the associations between the mRNA levels and the clinical, pathological and molecular tumour characteristics and the patients’ overall and relapse-free survival. Here, TGFB1 is linked to breast cancer.