RecruitingPhase 1Genetic interventionGPC2-CAR T Cell Therapy for Relapsed or Refractory Medulloblastoma in Children and Young AdultsThis is a single-site, open-label Phase I treatment study evaluating the manufacturing feasibility and safety of chimeric antigen receptor (CAR) T cells targeting the oncofetal protein Glypican-2 (GPC2) in pediatric and young adult patients with recurrent or refractory (R/R) medulloblastoma. Subjects with other non-medulloblastoma CNS embryonal tumors may enroll.