Target cell is a term given to one of three different concepts in medicine.
- In hematology, target cells are abnormal red blood cells, that have a bullseye appearance. (See main article: codocyte)
- In endocrinology, target cells can refer to the cells where hormones have their effect. Target cells are capable of responding to hormones because they bear receptors to which the hormone can bind. Hormones will float along the bloodstream until they find an appropriate target cell.
- In immunology, target cells are cells which present the antigenic peptide combined with MHC1 molecules to Cytotoxic T cells. These cells have class I MHC molecules on their surface (in contrast to Antigen Presenting Cells, which in addition also have the class II MHC MHC2 molecues). Target Cells are the normal cells of the body which have undergone some alteration and synthesise abnormal proteins e.g. tumor cells, virus infected cells.