Furthermore, gastric cancers with positive PD-L1 expressions are found to have higher FDG uptake than those with negative expressions, possibly due to the activations of hypoxia-inducible factor 1-alpha and peroxisome proliferator-activated receptor-gamma, which can upregulate both FDG uptake and PD-L1 expression [41]. The gene discussed is HIF1A; the disease is gastric cancer.