Quick Answer. A low hemoglobin count, also known as anemia, is caused by pregnancy, a menstrual period, a diet low in iron, blood loss, or a disease that causes the body to produce fewer red blood cells or to destroy red blood cells. According to the Mayo Clinic, medications also sometimes cause anemia.
A cytotoxic T cell (also known as TC, cytotoxic T lymphocyte, CTL, T-killer cell, cytolytic T cell, CD8+ T-cell or killer T cell) is a T lymphocyte (a type of white blood cell) that kills cancer cells, cells that are infected (particularly with viruses), or cells that are damaged in other ways.
1 These cells function as killer or cytotoxic cells because they are able to destroy target T-cells which express specific antigens that they recognize. 2  These cells are important in fighting viral infections and tumours. 3  Helper T-cells (CD4+) are middlemen in the immune response.he immune system is a complex system of interacting cells whose primary purpose is to identify foreign (ânon-selfâ) substances referred to as antigens. The immune system provides protection from infectious disease by identify most of these microbes as foreign.