Therefore, β‐RA should be preferentially considered for the treatment of human CoQ10 deficiency with accumulation of DMQ10, as it has been reported in patients with mutations in COQ9, COQ7, or COQ4 (Duncan et al, 2009; Freyer et al, 2015; Danhauser et al, 2016; Herebian et al, 2017b; Wang et al, 2017; Smith et al, 2018) but also in cells under siRNA knockdown of COQ3, COQ5 and COQ6 (Herebian et al, 2017b). The gene discussed is COQ9; the disease is hyperinsulinemic hypoglycemia, familial, 4.