Impact of CD27 and CD70 mutations in lymphocyte differentiation in vivo: lymphocytes and subsets. PBMCs from healthy controls (n = 18-26), CD27-deficient patients (n = 10), or CD70-deficient patients (n = 7-11) were labeled with mAbs against CD3, CD4, CD8, CD56, CD20, CD10, CD27, CD161, TCR Vβ11, TCR Vα7-2, TCR Vα24, CCR7, and CD45RA. (A) Proportions of total (CD3⁺), CD4⁺ (CD3⁺CD4⁺CD8⁻), and CD8⁺ (CD3⁺CD4⁻CD8⁺) T cells, B cells (CD20⁺), and NK cells (CD3⁻CD56⁺) in peripheral lymphocytes of healthy donors and patients. (B) Ratio of CD4/CD8 T cells. (C) Proportions of CD3⁺ T cells expressing αβ or γδ TCR. (D-E) proportions of MAIT (D) or NKT (E) cells within the total CD3⁺ T-cell population. (F) Proportions of CD56^high and CD56^dim NK subsets within the total NK population. (G) Proportions of transitional, naive, and memory B cells within the total B-cell population. (H-I) Proportion of CD4⁺ (H) and CD8⁺ (I) cells with a naive, T_CM, T_EM, or T_EMRA phenotype. Statistics performed using ANOVA. *P < .05; ** P < .01; ****P < .0001.