In a prospective trial of HNSCC patients undergoing chemoradiation, HIF1α expression correlated with an increase in intratumoral FMISO uptake during the first 2 weeks of chemoradiation, and high levels of HIF1α and CAIX were associated with a delayed resolution of the FMISO uptake between weeks 2 and 5 [6]. The gene discussed is HIF1A; the disease is head and neck squamous cell carcinoma.