This study enrolls patients with newly diagnosed differentiated thyroid cancer (papillary thyroid cancer or follicular thyroid cancer) that has spread to the lungs and has a genetic mutation called RET fusion. The study involves taking a study drug called selpercatinib for approximately 6 months prior to receiving radioiodine therapy (RAI). The overall goal of this study is to find out if taking the study drug before RAI works better than receiving RAI alone (the usual standard of care treatment).

The purpose of this study is to evaluate the effects, good or bad, of targeted therapies or immunotherapy (drugs that help the body's immune system fight cancer cells) in patients who have solid tumors with specific genetic alterations or with a high number of mutations. Patients will be assigned to cohorts (groups) based on having a specific type of genetic alteration in their tumor. The study includes cohorts for patients whose tumors have genetic alterations in the ROS1, NTRK, PIK3CA, BRAF, or RET genes or a high number of mutations in their tumor.

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.

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

This study enrolls patients that have been diagnosed with SMARCB1 or SMARCB4 deficient cancer that has either come back (relapsed) or does not respond to therapy (is refractory) or have been newly diagnosed with a SMARCB1 or SMARCB4 deficient cancer that has no known standard treatment. This study involves taking study drugs called tiragolumab and atezolizumab. These drugs are a type of immunotherapy that try to make the immune system fight cancer. The purpose of the study is to learn more about the safety of tiragolumab in children and to see how well the combination of tiragolumab and atezolizumab works when given to children and adults with these types of tumors. This study has two parts. In Part A, participants will receive tiragolumab. In Part B, participants will receive both tiragolumab and atezolizumab.