RecruitingClinical trialIdentification of Specific Molecular Signatures in Pediatric, Adolescent, and Young Adult Rhabdomyosarcoma Through Spatial Proteome Analysis Using Mass SpectrometryThis non-interventional study aims to develop spatial proteomics for analyzing small FFPE tumor samples in rhabdomyosarcoma. It will identify molecular signatures linked to tumor regions, subtypes, survival, and treatment resistance, using pre-existing samples and data.