In human genetic linkage studies, association studies frequently involve the comparison of allele frequencies for a marker locus between a disease population and in a control population. A disease whereby an individual's immune system mounts an attack on a portion of its own tissues. Tissues undergoing such an attack can be destroyed in the process. Rheumatoid arthritis is an example of an autoimmune disease. Tissue taken from one part of an individual organism's body and then moved or transplanted to another location within that same organism.
Skin transplants are a common example.
Autografts are also used when bone marrow is harvested from an individual and stored for later use. This marrow tissue is transplanted back into the donor to replace tissue destroyed during chemotherapy. Humans have 22 pairs of autosomes in each cell.