CXCR4 and lung cancer: As shown in Fig. 6A, surface expression of CXCR4 protein on lung cancer cells harboring the EGFR-L858R mutation (median, 12.61; range: 8.95–34.56) was significantly higher than that in EGFR-WT cells (median, 5.36; range, 2.00–12.58; P = 0.025, Mann-Whitney U Test).