RS-PDX models molecular profiling. (A) Representative immunohistochemistry images of PI3K-δ/γ and Bcl-2 expression in lymph nodes and bone marrow biopsies of patients with RS (magnification ×40; insets ×4). (B) Percentage of PI3K-δ/γ and Bcl-2 positive cells in a cohort of 24 RS primary samples. Dashed line indicates the 50% threshold used to define positive samples. (C) Western blot panels showing expression of proteins belonging to the BCR and PI3K cascades (p110δ, p110γ, p85α, p101, p-BTK, BTK, p-AKT, AKT, c-Myc) and apoptotic pathway (Bcl-2, Mcl-1) in the available RS-PDX models (RS1316, IP867/17, RS9737, RS1050). Bar plots represent intensity of p110δ, p110γ, and Bcl-2 bands in 4 independent experiments. Band intensities were measured using Image Lab and normalized on β-actin. Data are reported as mean ± standard error of the mean (SEM). (D) Quantitative reverse transcriptase polymerase chain reaction analyses of members of the PI3K family (PIK3CD, PIK3CG, PIK3R5), apoptotic pathway (BCL2, MCL1), and MYC. Messenger RNA expression is normalized over β-2-microglobulin (B2M). Data are reported as mean ± SEM. RE, relative expression. Statistical analysis was performed using 1-way analysis of variance (ANOVA); *P < .05, **P < .01, ***P < .001, ****P < .0001.