CD274 and lung cancer: For 9 tissue biopsies having available PD-L1 IHC staining results, 5 samples were PD-L1 positive, including two high-expression samples and three low-expression samples (Fig. 3), and the frequency is comparable to the overall positive ratio in lung cancer 24, which shows no correlation between METex14 alteration and PD-L1 overexpression.