Additionally, CD3 on CD45RA+ CD4+ was also found to be positively related to the increased risk of HT onset (OR = 1.041, 95% CI = 1.009–1.075, P = 0.012), but the association was not supported by weighted median (OR = 1.039, 95% CI = 0.994–1.086, P = 0.087) and MR Egger (OR = 1.038, 95% CI = 0.992–1.086, P = 0.119). This evidence concerns the gene CD4 and hematocrit.