Fig. 1

Study workflow, overview of patients and samples, and cohort characteristics. a Overview of patient cohorts and various experimental platforms. b A representative patient with primary lung cancer (DHP18) who later developed brain metastasis. A primary lung lesion was detected by CT scan and surgical resection was performed to obtain the primary lung cancer sample. However, 1 year after the surgery, a new brain metastasis lesion was identified through MRI scan. The surgical resection was then performed to remove the brain metastatic lesion