Lenalidomide activates T cells in vivo and does not alter CD20 expression. (A) HLA-DR expression was measured by flow cytometry in peripheral blood on CD4 and CD8 T cells at various time points. (B) CD20 expression was measured by flow cytometry on circulating normal and/or malignant B cells. End of induction was 28th day of sixth cycle of treatment. Median value is depicted as a black bar. *P ≤ .05, ***P ≤ .001. C1D1, first day of first treatment cycle (before lenalidomide intake); C1D8, eighth day of first cycle (before or after obinutuzumab [GA101] infusion); C2D1, first day of second cycle (before lenalidomide intake); MFI, mean fluorescence intensity; ns, not significant.