We isolated CD44+ BrM-CSCs from the previously established brain metastatic subpopulations (BrM) that were derived from a human lung adenocarcinoma cell line PC9 both in a preclinical model (PC9-BrM3, Figure S1A) and a novel bionic microfluidic chip (PC9-BrMchip, Figure S1B-C) by flow cytometry 9, 10. The gene discussed is CD44; the disease is lung adenocarcinoma.