When KEGG pathway analysis was similarly performed on the 8 differentially expressed microRNAs between the patients with sporadic PMAH and normal controls, the renal cell carcinoma, dilated cardiomyopathy, axon guidance, ubiquitin-mediated proteolysis, endocytosis and MAPK signalling pathways were ranked as the most affected pathways on the basis of the predicted targets, while the renal cell carcinoma pathway contained 5 genes (CDC42, CUL2, EP300, GRB2 and SLC2A1) that were predicted to be potential downstream targets of the differentially expressed microRNAs (Fig. 5B). The gene discussed is GRB2; the disease is dilated cardiomyopathy.