The average number of CD4+ T cells in adult blood is 1100 / mcL (range, 300 to 1300 / mcL [1.1 × 10 9 / L with a range of 0.3 to 1.3 × 10 9 / L]), and the average number of cells of the other major T-cell subgroup, CD8+ (suppressor) T cells, is 600 / mcL (range, 100 to 900/mcL).