The green fluorescence in internal tumor (in rectangular box) was observed in PBS (−) and PBS (+) groups, whereas weak green fluorescence can be found in NP+PD‐1 (+) group, indicated that Hb@Hf‐Ce6 NPs can dramatically relieve hypoxia and improve the treatment effect under X‐ray irradiation. This evidence concerns the gene PDCD1 and neoplasm.