Fig. 1.

Flow chart of the study design. The study cohort included 29 patients with advanced NSCLC that metastasized to the brain parenchyma (n = 18) or leptomeninges (n = 11) and 31 patients with advanced NSCLC who never developed CNS metastasis until death. All patient samples were collected before systemic treatment and subjected to capture-based targeted genomic sequencing with a 520-gene panel and targeted bisulfite sequencing with an 80,672 CpG DNA methylation panel. Asterisks denote the 2 cerebrospinal fluid (CSF) samples and 4 lung tumor samples that failed quality control and were excluded from somatic mutation profile analysis