Importantly, we observed a positive correlation between the expression levels of MAF and those of FGF18, PTHLH, JAG1, TMEM2, TGFA, JAK1 and SHH in ER+ BCa-patient gene expression datasets, including the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) and The Cancer Genome Atlas (TCGA) BCa cohorts13,38,39 (Fig. 3f). This evidence concerns the gene FGF18 and breast cancer.