NDUFA13 and Obesity: Moreover, because GRIM-19 also functions as a potent regulator of energy metabolism (43) and because sensitivity to metabolic cues in LCs exert a major influence on spermatogenesis and biosynthesis of testosterone (53), failure of testis GRIM-19 expression to decline in a progressive fashion might contribute to the well-known exacerbation of androgen deficiency in aged males (54), some of which occur in the context of obesity (55) or diabetes (56).