In diabetes, counts of TRPV1 immunoreactive fibres per mm length of tissue section showed a significant decrease in both epidermis and sub-epidermis [median (range) Epidermis: control 1.2 (0.0–2.6), diabetic 0.0 (0.0–0.6); p < 0.01; Sub-epidermis: control 4.4 (0.2–11.1), diabetic 0.4 (0.0–3.4); p < 0.01; Fig 9A,B]. This evidence concerns the gene TRPV1 and diabetes mellitus.