As the therapeutic landscape for chronic lymphocytic leukemia (CLL) continues to expand, biological predictors of response to therapy are becoming increasingly important, according to a recent review.

The immunoglobulin heavy chain (IGHV) gene is a powerful predictor of duration of response and overall survival with chemoimmunotherapy (CIT). The authors note that it is critical that providers understand how mutational status is determined, as well as the limitations of testing. They describe the details of IGHV mutational status testing, highlighting the best way to interpret this information and apply it to care.