Wang P, Zhang H, Chen P, et al. - Researchers conducted the study for analyzing the genomic instability in cerebrospinal fluid (CSF) in patients with meningeal metastasis (MM). Blood and CSF samples were collected from 15 MM patients and one brain parenchymal metastasis patient. In MM patients, there was a significant difference in gene mutation between CSF cfDNA and plasma cfDNA. Twelve of the MM patients displayed genomic instability in their CSF cfDNA, whereas the other three had a stable genetic profile. Genomic instability was found in MM patients' CSF cfDNA rather than plasma cfDNA, which could be the underlying cause of the differences in MM.