CDKN2A and neoplasm: Why RGNT are low-grade neoplasms with mostly indolent behavior despite the selection for and acquisition of multiple pathogenic mutations involving two mitogenic signaling pathways remains unknown, but may involve having intact cell cycle regulators such as CDKN2A and absence of telomere maintenance mechanism (e.g. TERT promoter mutation or ATRX inactivation) that protect against uncontrolled proliferation and malignant transformation.