BRAF and central nervous system cancer: In this study, we analyzed circulating tumor DNA (ctDNA) from 78 liquid biopsies (plasma n = 44, cerebrospinal fluid n = 34 (CSF)) of 35 glioma patients, determining H3F3A K28M (K27M) and BRAF V600E mutation allele frequency using droplet digital PCR (ddPCR).