BDNF and cancer: Gene set enrichment using The database for annotation, visualization and integrated discovery (DAVID) [45,46] revealed that the breast cancer LCC was significantly enriched in FGF, MAPK, Erb, neurotrophin, B-cell and T-cell receptors signaling pathways (6.03 × 10−5 < p < 0.018), as well as in several KEGG cancer pathways (3.4 × 10−4 < p < 0.048) (Table S2).