Autologous T cell–CLL B cell (CLL B cells stained blue) conjugates (with or without sAg) from 4 patients before and after treatment with lenalidomide (Days 2, 3, 5, 8, and 12) were selected at random for imaging and scored for accumulation of F-actin (red) at the immune synapse. Fifty conjugates were analyzed per experiment. Original magnification, ×63.