As to the comparison between the exon 19 deletion-positive and the L858R mutation-positive groups from stage IIIB-IV patients, there was a slightly longer median OS (20.6 vs.14.2 months, P of log-rank test = 0.368) in the former (Figure 2D), but no difference in the cumulative incidence of SBM (39.5% vs. 34.5%, HR= 1.12, 95% CI = 0.60-2.09, P = 0.720, Figure 2E) was observed between the two groups.