In addition, EGFR 19del mutation [HR = 0.684, 95% CI (0.504–0.928), p = 0.015], a history of lung cancer surgery [HR = 0.558, 95% CI (0.381–0.816), p = 0.003] and no bone metastasis [HR = 0.673, 95% CI (0.498–0.911), p = 0.010] were significantly associated with longer OS (see Figure 3B). Here, EGFR is linked to bone metastasis.