The present results confirmed this idea by adding the evidence that the activation of PKC activity by phorbol 12,13-dibutyrate (PDBu) only impaired endothelial relaxations in the CC of ED patients without diabetes but not in that of diabetic ED patients, while the inhibition of PKC with GF109203X improved endothelial relaxation only in diabetic tissues. Here, PRRT2 is linked to diabetes mellitus.