Fig. 1: Schematic illustration of the study design.

LCBM non-small cell lung cancer (NSCLC) brain metastasis (BM), LM single organ liver metastasis, BoM single organ bone metastasis, ALC advanced NSCLC without distant organ metastasis, ELC early-stage NSCLC, PBT primary brain tumours, HG healthy group. Corresponding non-tumour is matched with patient of NSCLC without BM.