STAT1 and neoplasm: Phyh (peroxisomal phytanoyl-CoA dioxygenase) regulates peroxisomal fatty acid β-oxidation metabolism and ROS conversion (105); its concentration positively correlates with potential tumour suppressive environment (106, 107), working synergistically with iNOS induced by Stat1, which may trigger the recruitment of CTLs (108, 109).