RB1 and lung carcinoma: These findings, combined with our results, support the hypothesis that exosomal miR-550a-3-5p may regulate cell viability, apoptosis, cell cycle, and migration of HBMECs by mediating cleaved-PARP, pRB, CDK6, CTGF, and CYR61 expression, consequently influencing brain metastasis of lung cancer.