This study involves an investigational cellular therapy called Afamitresgene Autoleucel. The overall goal of this study is to find out how safe and effective this cellular therapy is in treating people that have been diagnosed with synovial sarcoma, malignant peripheral nerve sheath tumors (MPNST), neuroblastoma or osteosarcoma that has grown or returned after being treated.

The purpose of this study is to determine whether AUTO1, an experimental form of therapy, is safe and effective in helping the immune system fight cancer. AUTO1 uses immune cells, called T cells, that are collected from the blood using a process called leukapheresis and then modified in a lab to recognize and target cancer cells. These modified cells are then put back into the body through infusion.

This study enrolls patients between 5 and 40 years of age with a diagnosis of any sarcoma that has progressed on or relapsed after upfront initial therapy. The purpose of this study is to find the best dose of a drug called cabozantinib ("the study drug") to give to patients in combination with a routine chemotherapy drug called ifosfamide.

This study involves taking a study drug called INBRX-109. The overall goal of the study is to find out how safe and effective the study drug is in treating people that have been diagnosed with advanced or metastatic Ewing sarcoma or SDH-deficient solid tumor/Gastrointestinal Stromal Tumor (GIST).

This study involves taking a study drug called lurbinectedin. The overall goal of this study is to see if different doses of lurbinectedin are safe and effective at treating children and young adults with recurrent or relapsed solid tumors, including Ewing Sarcoma.

The purpose of the Phase 2 portion of this study is to evaluate the safety and efficacy of the study drug called palbociclib when given in combination with two other drugs (temozolomide and irinotecan) in patients with Ewing sarcoma and when given in combination with topotecan and cyclophosphamide in patients with neuroblastoma.

This study enrolls patients with refractory, progressive, or relapsed solid tumors. The purpose of this study is to find out whether a drug called PEEL-224 ("the study drug") is safe and effective when given as monotherapy (a drug given by itself) and as part of a combination therapy together with other chemotherapy drugs.

The purpose of this study is to test an experimental approach called cell therapy for neuroblastoma. This study will take a patient's own white blood cells (T cells) and change them to turn against the cancer. CART cells have been used to treat other cancers, but PHOX2B CART cells have not been administered to human patients prior to this clinical trial. Participants will be given PHOX2B cells via an IV and then monitored for up to 12 months.

Participants will also be asked to sign consent to a separate long term follow-up protocol to monitor their health for up to 15 years after their last PHOX2B CART treatment.

This study has two parts. Part A enrolls patients who have been diagnosed with a solid tumor, lymphoma or desmoid tumor that has either come back ("relapsed") or does not respond to therapy ("is refractory"). Part B enrolls patients with a relapsed or refractory Ewing sarcoma, desmoid tumor, osteosarcoma, liver tumor, Wilms tumor, or tumors with changes in a gene family known as the Wnt pathway. This study involves taking a study drug called tegavivint. The study will be testing different doses of the study drug to find the safest dose.