Mice at advanced stages of the disease (ie, pBIC mice at 180 days with incipient splenomegaly) were randomly enrolled in the experimental groups and treated intraperitoneally either (1) once a week with 200 µg of anti-mouse CD20 (10 mg/kg, clone 5D2, isotype IgG2a, Genentech); (2) twice a week with 250 µg/dose of venetoclax (10 mg/kg, ABT-199, Chemieteck); (3) with a combination of both anti-mouse CD20 and venetoclax; or (4) twice a week with 50 µL of DMSO as the vehicle for venetoclax solubilization, corresponding to the untreated (UNT) experimental group. Treatment regimens were divided into two modalities: (1) to study overall survival, mice were treated for eight consecutive weeks and then reviewed periodically until moribund and appearance of ethical end-point criteria or (2) to study the ongoing effect of the treatment in the tumor cells and the TME, mice received four consecutive weeks of treatment (half-of-treatment duration) and then they were sacrificed and submitted to the characterization of primary tissues. Additionally, an independent cohort of pBIC mice were either untreated or treated intraperitoneally once a week with 200 µg anti-mouse PD-1 (10 mg/kg, clone RMP1-14, isotype IgG2a, BioXcell) for 2 weeks, before primary tissues were analyzed for IFN-γ expression.