This document discusses graft versus host disease (GVHD), a condition that can occur after stem cell or organ transplantation where the donated cells or organ is rejected by the recipient's body. There are two main types of GVHD - acute and chronic. Acute GVHD develops within 100 days after transplantation and can affect the skin, gastrointestinal tract, or liver. Chronic GVHD can involve single or multiple organs and is a leading cause of health problems and death after stem cell transplants. While acute GVHD is often treated successfully with corticosteroids, chronic GVHD may require additional treatments such as Ibrutinib, Belumosudil, or Ruxolitinib that have been approved