CD274 and gastric cancer: It was shown that isolated CSV+CTCs (Fig. 5A) and EpCAM+CTCs (Fig. 5B) were validated by the presence of PD‐L1 expression on the membrane and in cytoplasm, however, most of EpCAM‐enriched CTCs were observed with negative expression of PD‐L1 in GC patients with early disease (Fig. S3).