Correlation between the percentage of CCR7⁺ cells after stimulation and clone expansion. The 28 anti–MAGE-3.A1 clones were stimulated with MZ2-MEL.43 tumor cells pulsed with the MAGE-3 peptide and IL-2. Samples were collected 48 hours after stimulation. Cells were labeled with an APC-conjugated anti-CD8 antibody and either an FITC-conjugated anti-CCR7 antibody or a control isotype-matched antibody. Surface expression of CCR7 is expressed as the percentage of the cells having a fluorescence intensity above 99% of the cells labeled with the control isotype-matched antibody. Expansion was estimated by counting the number of CD8⁺ cells at days 2 and 5 by flow cytometry. The best correlation curve and the coefficient of determination (R²) are indicated.