Immunoglobulin kappa chain as an immunologic biomarker of prognosis and chemotherapy response in solid tumors.

Infiltration of plasma cells is associated with better prognosis in breast, lung and colon cancer. Immunoglobulin κ chain (IGKC) is now available as a single, robust immune marker predicting metastasis-free survival and response to chemotherapy. This will facilitate a deeper understanding of the role of the humoral immune system in cancer development.