RB1 and malignant peripheral nerve sheath tumor: We recently reported RABL6A negatively regulates the p27-RB1 pathway to promote MPNST pathogenesis, which guided preclinical drug studies that established the efficacy of CDK-targeted therapies in suppressing MPNSTs.19 Here, we verify the physiological importance of RABL6A signaling in driving MPNST progression in NF1-associated tumors.