NPC1 and cancer: Altogether, these findings delineate a novel hierarchic pathway in which inhibition of the mitochondrial function exerted by biguanides is epistatic to NPC, whereas mTORC1 acts downstream of NPC to control ACAD10 expression.[4] Demonstrating the probable evolutionary conservation of this route, the authors showed that NPC inhibition and ACAD10 upregulation were both required for limiting growth of human cancer cell lines treated with metformin.