GZMB and post-traumatic stress disorder: However, significance was lost when assessing the frequency of CD8dimCD3- cells expressing granzyme B in samples from only male subjects or only age-matched subjects, although the value for the males in the PTSD group remained lower (82.7 ± 12.2) than values for male controls (88.3 ± 8.3), and they remained lower in the age-matched analysis in the PTSD group (81.0 ± 6.9) than in the controls (90.2 ± 6.1).