Furthermore, a recent study has demonstrated intertumoural and temporal heterogeneity of PD-L1, as measured by [99mTc]NM-01 SPECT/CT, in patients with advanced NSCLC receiving anti-PD-1 therapy, and found that the baseline [99mTc]NM-01 tumour to blood pool ratio was predictive of early metabolic [18F]FDG-PET/CT response to anti-PD-1 therapy [33] (PD-L1 imaging highlighted in Fig. 2). The gene discussed is CD274; the disease is non-small cell lung carcinoma.