MT-RNR1 and type 2 diabetes mellitus: To confirm this, we obtained serum samples from healthy controls (n = 19, age 29.1 ± 6.8 years, female 26%) and patients with T2D (n = 45, age 64.7 ± 7.9 years, female 51%) to measure circulating MOTS-c levels (Fig. 3b and Supplementary Fig. 1).