In men, MNP accumulation in the testes is accompanied by spermatogenesis disruption through pyruvate and thyroid metabolism imbalance [202], destabilization of the blood-testis barrier through ROS/MAPK/Nrf2/p38/NF-κB activation [205], and suppression of the hypothalamic-pituitary-gonadal (HPG) axis through reduced testosterone and LHR/cAMP/PKA/StAR [52], clinically manifesting as oligozoospermia and asthenozoospermia, confirmed by the detection of PS, PE, and PVC in semen [207,208,209]. The gene discussed is MAPK14; the disease is Reduced sperm motility.