COA3 and neoplasm: Alternatively, the second hypothesis for explaining the increase in tumor invasion in women would be the fact that the reduced level of miR-338-3p (secondary to its binding to the rs4702 G allele [32] and to the effect of estrogens [45]) is known to be positively associated with lymph node metastasis in many solid tumors [52,53,54], possibly through an upregulation of COA3, a mitochondrial transmembrane protein [54].