Figure 2.

NK cell population was quantified by flow cytometry. (a) The NK cell population was sequentially increased on aging in both genders. (b) However, the NK cell population was considerably decreased in the female gender at almost all different age points compared with that in the male gender. (c) Flow cytometry images of CD56-positive NK cell populations at different age points. P > 0.05. ^∗Between age groups, compared to the corresponding 41–50 age group. ^#Among males compared to ages 41–50.