The E/NSCLC patients, one with 3.4% EGFR+ and 10.5% CXCR4+ serum sEVs and the other with 4.1% EGFR+ and 12.6% CXCR4+ serum sEVs, both had nearly negative EGFR staining and low CXCR4 staining in the primary tumor tissue (Figure 3C and Supplementary Figure S9A). Here, CXCR4 is linked to non-small cell lung carcinoma.