Figure 2. Gene expression analysis showing top 51 up- and down-regulated biological pathways in CD4+ T cells between older (70 to 80 years-old) and younger (20 to 30 years-old) men. Mitochondria-related and oxidative phosphorylation-related pathways were the most down-regulated pathways in older compared to younger donors. Differences of Z-scores between younger and older participants are shown on the X-axis. Each row denotes a different pathway (p ≤ 0.05 and FDR ≤ 0.3). N = 5 young, 19 old donors.