The differentially expressed genes (adjusted P-value < 0.05, cancer vs normal) in the clusters are significantly enriched in 10 well-known breast cancer-related pathways, including apoptosis, cell cycle, estrogen signaling, IL − 17 signaling, neurotrophin signaling, NF − kappa B signaling, NOD − like receptor signaling, p53 signaling, PI3K − Akt signaling and TNF signaling pathways (Supplementary Fig. 4B). Here, BDNF is linked to breast cancer.