Samples from patients with intermediate- or high-grade non-Hodgkin's lymphoma are analyzed by three-stage immunohistochemistry using monoclonal antibodies to B-cell antigens, T-cell antigens, immunoglobulins, CALLA, HLA-DR, anti-interleukin-2 receptor, and Ki-67 (for the proliferative index). Phenotype (immune marker status, proliferation status, and activation status) is correlated with response to treatment, relapse, and overall survival.