CD4⁺ T-cell recovery in ICL patients upon therapeutic administration of IL-2. Changes in absolute leukocyte counts cells in 1 ICL patient (P1) during 4 courses of recombinant IL-2 treatment. (A) Lymphocytes, CD4⁺ T and B lymphocytes. (B) CD3⁺ and CD8⁺ T lymphocytes and NK cells. Arrows indicate IL-2 administration.