Biocompatibility is related to the behavior of biomaterials in various environments under various chemical and physical conditions. The term may refer to specific properties of a material without specifying where or how the material is to be used. For example, a material may elicit little or no immune response in a given organism, and may or may not able to integrate with a particular cell type or tissue. Immuno-informed biomaterials that direct the immune response rather than attempting to circumvent the process is one approach that shows promise. The ambiguity of the term reflects the ongoing development of insights into "how biomaterials interact with the human body" and eventually "how those interactions determine the clinical success of a medical device (such as pacemaker or hip replacement)". Modern medical devices and prostheses are often made of more than one material, so it might not always be sufficient to talk about the biocompatibility of a specific material. Surgical implantation of a biomaterial into the body triggers an organism-inflammatory reaction with the associated healing of the damaged tissue. Depending upon the composition of the implanted material, the surface of the implant, the mechanism of fatigue, and chemical decomposition there are several other reactions possible. These can be local as well as systemic. These include immune response, foreign body reaction with the isolation of the implant with a vascular connective tissue, possible infection, and impact on the lifespan of the implant. Graft-versus-host disease is an auto- and alloimmune disorder, exhibiting a variable clinical course. It can manifest in either acute or chronic form, affecting multiple organs and tissues and causing serious complications in clinical practice, both during transplantation and implementation of biocompatible materials.