Methods for treating diffuse large b-cell lymphoma and the use of biomarkers as a predictor of responsiveness to drugs

In one aspect, provided herein are methods for predicting the responsiveness of DLBCL patients to treatment with lenolidomide or Compound A; or a stereoisomer thereof; or a pharmaceutically acceptable salt, solvate, hydrate, co-crystal, clathrate thereof; or a polymorph thereof utilizing biomarkers or classfiers that correlate with responsiveness to one of these drugs. In another aspect, provided herein are methods for treating a DLBCL patient determined to be responsive to treatment with lenolidomide or Compound A; or a stereoisomer thereof; or a pharmaceutically acceptable salt, solvate, hydrate, co-crystal, clathrate thereof; or a polymorph thereof utilizing biomarkers or classifiers (or output thereof) that correlate with responsiveness to one of these drugs.