EGFR and bone metastasis: A consistent benefit of EGFR-TKI plus thymosin over EGFR-TKI with respect to PFS (Figure 2) and OS (Figure 3) were shown across most subgroups that were assessed, including the subgroups based on age, EGFR mutation type (exon 19 deletion vs. exon 21 L858R mutation), the presence or absence of CNS metastases, multiple lung metastasis, pleura metastasis, bone metastasis and adrenal metastasis, treated by gefitinib or erlotinib.