The function of T cells is to perform a variety of immune responses in the body, according to National Multiple Sclerosis Society. T cells are one of two types of white blood cells that help immune function.
T-cell count is the blood test that measures the number of the lymphocytes, a type of white blood cell in the human body. Since these cells work to fight off diseases, a low or high T-cell count means the immune system is compromised, notes Healthline.
There are normally between 500 and 1,000 T-cells per cubic millimeter of blood, according to AIDS.gov. T-cells send signals that activate the body's immune response when there are viruses or bacteria in the body.
Animal cells are eukaryotic cells, or cells that contain a membrane-bound nucleus. The nucleus holds the DNA of the cell that provides the cell with instructions for life.
A normal T-cell count should be in the range of 500 to 1,000 T-cells per cubic millimeter of blood, according to Healthline. Higher or lower ranges may call for additional testing to determine a cause or diagnosis.
Best Buy sells a variety of AT&T cell phones, including the iPhone 6. Other AT&T cell phone brands that Best Buy carries are Samsung Galaxy S6 and Samsung Galaxy S5, as of 2015.
AT&T has cell towers in most of the United States' largest metropolitan areas, such as New York City, Los Angeles, Chicago, Dallas and Houston. AT&T also has cell towers in Philadelphia, Miami, Atlanta, Boston and Washington, D.C.