Thus, in the present study, our HD group was not only analysed as a whole group; it was also analysed following the division into groups of HD patients with type 2 DM and without DM and into groups of HD patients with D and without D. We showed that there was no difference in plasma eNOS concentrations between the HD patients with type 2 DM and without DM (despite the significant difference in the HbA1c levels, p < 0.00001) or between the HD patients with D and without D. The gene discussed is NOS3; the disease is Huntington disease.