Improving Outcomes Assessment in Chronic GVHD

Inclusion Criteria: * Age greater than or equal to 2 years * Prior allogeneic stem cell transplant, with any graft source, donor type, and GVHD prophylaxis allowed * Clinical or histologic diagnosis of chronic GVHD (overlap syndrome with acute GVHD is allowed * Need for systemic treatment, defined as any medication or intervention delivered systemically, including extracorporeal photopheresis. If a patient only received topical or local therapy at diagnosis, but subsequently requires systemic treatment, they may be enrolled upon initiation of systemic therapy. (Note, these patients will be classified as incident or prevalent cases depending on time from chronic GVHD diagnosis, not start of systemic therapy) * If a prevalent case (defined as enrollment three or more months after chronic GVHD diagnosis), then subject must be within 2 years of stem cell infusion * If an incident case (enrollment less than 3 months after chronic GVHD diagnosis) then no limitation on time from transplantation * No evidence of primary disease relapseProgression-free for their malignancy at enrollment (no evidence of primary disease progression since transplant, although residual disease may still be present) * Evaluation at the transplant center at the time of study enrollment * Signed, informed consent and if applicable, child assent Exclusion Criteria: * Inability to comply with study procedures * Anticipated survival less than 6 months due to co-morbid disease