BCR and B-cell chronic lymphocytic leukemia: In order to further understand T cell compartment dynamics in CLL, we extended our studies to longitudinal investigation (pre/post-treatment) of patients treated with chemoimmunotherapy with the fludarabine-cyclophosphamide-rituximab (FCR) regimen or the BcR signaling inhibitors (BcRi) ibrutinib (IB) and idelalisib (the latter in combination with rituximab, R-ID).