MAIT cells are nonproliferating cells. (A) Representative Ki67 intracellular staining of CD4, CD8 T, or MAIT cells (left panel) and proportion from 3 different donors (right panel). (B) Representative Vα7.2-CD161 staining of freshly sorted MAIT cells (left panel) and after 10 days of culture in the presence of phytohemmaglutinin + IL-2, Il-7, and IL-15 (middle panel). CFSE pattern gated on MAIT (CD161⁺Vα7.2⁺) and CD161⁻Vα7.2⁺ cells after the 10-day culture period (right panel). (C) Proportion of CFSE^low cells in MAIT cells and CD161⁻Vα7.2⁺ subset at day 10 in 5 independent experiments. (D) Vα7.2Jα33 transcript expression on sorted CD161⁺Vα7.2⁺ and CD161⁻Vα7.2⁺ at day10. Expression is normalized to that of freshly sorted MAIT cells.