This study is for participants who have been diagnosed with a brain tumor called either a medulloblastoma or Central Nervous System embryonal tumors of the brain or spinal cord. The investigational drugs used in this study are thiotepa, etoposide and carboplatin. The purpose of this study is to test tumor for biologic markers that will help us know how to best treat each subject on this treatment study. Participants can expect to be on this study for up to 5 years and followed until end of study or disease progression.

This study is for patients that have been diagnosed with Epstein-Barr Virus associated Post-Transplant Lymphoproliferative Disorder (EBV-PTLD). The investigational drug in this study is tabelecleucel. Tabelecleucel is a product containing special immune allogeneic cells, called EBV-Cytotoxic T Lymphocytes (EBV-CTLs), that are made in the laboratory starting with cells from a healthy person who is immune to EBV. The purpose of this study is to test how well tabelecleucel works to treat EBV-PTLD following SOT in patients who have not responded to rituximab or rituximab plus chemotherapy treatment and to see what side effects happen. Your participation will help us to understand more about tabelecleucel. In the first 12-month period, participants will be asked to come to the clinic for an estimated 11 to 19 study visits and a minimum of 2 scans, depending on the number of cycles of treatment they are given. After treatment is done, participants will enter into the follow-up phase, and will continue to come into the clinic for scheduled check-ups for up to 24 months after the first dose of tabelecleucel was given. Participant information on the status of their disease and any new treatment will be collected for up to an additional 3 years. Participants can expect to be in this study for up to five years total.

The aim of this multi-site study is to evaluate the effectiveness of mHealth intervention strategies for improving anti-epileptic drug adherence in caregivers of young children with epilepsy. A 2-month baseline period will be followed by two stages. In Stage 1 (3-months), caregivers will received either 1) a mHealth education module and automated digital reminders or 2) the mHealth education module, automated digital reminders, and individualized adherence feedback based. In Stage 2 (2-months), caregivers will either receive 1) continued individualized adherence feedback or 2) individualized adherence feedback and a mHealth problem-solving module. The primary outcome is electronically-monitored adherence. Secondary outcomes include seizure severity/frequency, quality of life and healthcare utilization.

This study is for patients that have been diagnosed with multisystem Langerhans cell histiocytosis (LCH). The purpose of this study is to find out if prolonging the treatment and adding a drug called 6-mercaptopurine will be beneficial. Other goals include fining out if these changes will result in fewer patients having relapse of their LCH, and fewer patients having long term disease related problems. Participants can expect to be in this study for up to 24 months and will be followed on this study fir at least 5 years.

This study is for patients that have been diagnosed with Leukemia or Lymphoma. and have been treated on one of the following studies: Pediatric Oncology Group (POG) 9404, 9425, 9426, or Dana Farber Cancer Institute (DFCI) ALL Consortium 95-01. The purpose of this study is to look at the heart function of patients selected by change to get DRZ compared to the heart function of patients selected by chance not to get DRZ. In this study, they will also look at gender, age at cancer diagnosis, current age, dose of chemotherapy, and if chest radiation influences the risk of early heard damage. Participants in this clinical trial are expected to come to one clinic visit.

This study will assess the features of children, younger than 12 years old, with moderate to severe eczema, also known as atopic dermatitis, when their condition is not adequately controlled with topical therapies (creams or lotions) or when those therapies are not medically advisable.

This is not a treatment study. You and your child will complete questionnaires describing how their condition effects them. Information related to your child's illness will be collected by reviewing their medical chart and by assessments performed by the study team. Participation in this study will involve at least 12 visits that will take place over a period of 10 years.

The information collected in this study may lead to an improved understanding of your child's illness and may provide healthcare providers with important information for treating atopic dermatitis in the future.

This study is for patients that have been diagnosed with Germ Cell Tumors. The purpose of this study is to evaluate whether a strategy of complete surgical resection followed by surveillance can maintain an overall survival rate of at least 95.7% at two years for pediatric, adolescent and adult patients (ages 0- 50 years) with Stage I (low risk) malignant germ cell tumors, and at least 98% for patients with ovarian pure immature teratoma. The drugs used in this study are carboplatin and cisplatin. Participants will be followed for up to 10 years.

This study is for patients who have been diagnosed with a form of Acute Lymphoblastic Leukemia (ALL) called Philadelphia chromosome positive (Ph+) ALL. The purpose of this study is to compare disease free survival (DFS) of Standard Risk (SR) pediatric Ph+ ALL treated with continuous imatinib combined with either a high-risk COG ALL chemotherapy backbone or the more intensive EsPhALL chemotherapy backbone. A drug called imatinib in combination with chemotherapy will be given. Participants can expect to be in this study for up to 2 years and their health followed for up to 10 years.

This study is for patients that have been diagnosed with High Risk B-Lymphoblastic Leukemia (HR B-ALL). The investigational drug in this study is Ruxolitinib. The purpose of this study is to find out if the study drug, ruxolitinib, in combination with standard HR B-ALL treatment is safe and effective in children, adolescents, and young adults with HR B-ALL. Participants can expect to be in this study for the treatment period of approximately 26 months (females) or 38 months (males) plus the post-treatment follow-up. Subjects are considered on study during the post-treatment follow-up period until the subject is deceased, lost to follow-up, or until the study is completed. Subjects in this study will be followed until all enrolled subjects have been followed for 3 years from Day 1 or are deceased or lost to follow-up.

This is a study to determine the use of recombinant Von Willebrand Factor (rVWF) in the treatment and control of nonsurgical bleeding episodes and bleeding during elective and emergency surgery in children with severe Von Willebrand Disease. The study will last approximately 14 months and will involve regular visits to a research clinic.