Abstract: Disclosed herein, are methods, systems, compositions, arrays, and kits for using biomarkers, biomarker genes (e.g. EP300, MLL2, BCL-2, RB1, LRP1B, PIM1, TSC2, TNFRSF11A, SMAD4, PAX5, CARD11, ACTG2, LOR, GAPT, CCND2, SELL, GEN1, HDAC9, CD79B, MYD88, and ROS1) or biomarker gene expression levels for stratifying a patient having a hematological malignancy such as DLBCL for treatment, and administering a TEC inhibitor to selected patients. Also disclosed herein are methods, systems, compositions, arrays, and kits for using biomarkers, biomarker genes, or biomarker gene expression levels for monitoring a patient during treatment of a hematological malignancy such as DLBCL or FL or for optimizing a treatment regimen with a TEC inhibitor.