A study showed that dynamic changes in the BCRs pool may serve as a biomarker for predicting the clinical response to immunotherapy, and that the combination of anti-PD-1 and Toll-like receptor 9 (TLR9) agonists significantly increased the number of B cells in lymph nodes and the diversity of clonotypes of BCRs in a mouse model of colon and lung cancers, and that a reduction in the clonogenicity of the BCRs was negatively correlated with the effect of tumor suppression. This evidence concerns the gene TLR9 and lung cancer.