(2) HT patients’ Th17s expressed PD-1 at a significantly lower frequency than their counterparts in the NC [(6.46 ± 2.77)% versus (18.51 ± 3.96)%; t = −14.842, P < 0.001], while no difference was observed for PD-L1 between the two groups. This evidence concerns the gene CD274 and hematocrit.