SPATA18 and follicular thyroid adenoma: We have recently found that MIEAP was expressed in human thyroid non–oncocytic (conventional) follicular adenomas (FAs), but not in oncocytic FAs and conventional and oncocytic carcinomas (19), and therefore postulated that loss of MIEAP expression and a compensatory increase in mitochondria biogenesis induce the accumulation of mitochondria in thyroid oncocytic adenomas and cancers, however, in thyroid conventional cancers, the mitochondria are not accumulated despite defective MIEAP expression because of no compensatory increase in mitochondrial biogenesis.