CD8A and obesity due to melanocortin 4 receptor deficiency: The increases in adipose tissue T cells, particularly CD8+ T cells, were also observed in 11- to 16-months-old middle-aged mice (23, 45) and appeared to be influenced by sex, with females having a higher percentage of CD8+ T cells than males (45), in contrast with obesity, in which a greater change in adipose tissue T cells occurred in males than females (24).