(A) Western blot showing the expression level of MIC26 or/and MIC27 in the stable cell lines of HAP1 WT expressing empty vector (ev) and DKO that contain either of the following constructs, ev (pMSCVpuro), pMSCVpuro-MIC26, pMSCVpuro-MIC27, and both pMSCVpuro-MIC26 and pMSCVpuro-MIC27 together. (B) Oxygen consumption rates (pmol O2/s), including basal respiration (Basal), proton leak, maximal respiration (Maximum) after uncoupling by FCCP, spare respiratory capacity (Spare capacity), non-mitochondrial respiration (Non-mitochondrial), and ATP production are shown for HAP1 WT+EV (empty vector) and DKO+EV, DKO+MIC26, DKO+MIC27, DKO+MIC26+MC27, and DKO+CRLS1. Data are normalized to basal respiration from HAP1 WT+EV and the mean ± SEM from three independent experiments is shown. Overexpression of both MIC26 and MIC27 in DKO cells significantly rescued respiration of DKO cells. *P-value ≤ 0.05, **P-value ≤ 0.01 (t test).