Pathways in cancer, ErbB signalling, insulin signalling, adipocytokine signalling pathway, focal adhesion, renal cell carcinoma, aldosterone‐regulated sodium reabsorption, neurotrophin signalling, Fc gamma R‐mediated phagocytosis and transforming growth factor (TGF)‐beta signalling were co‐regulated by down‐regulated miRNAs (hsa‐miR‐4324, hsa‐miR‐203a, hsa‐miR‐199b‐5p) (Table 3). The gene discussed is BDNF; the disease is cancer.