B16‐F1 is a well‐characterized, highly aggressive murine melanoma cell line, and CD8+ T cell responses initiated against Ag derived from this melanoma at late stages of tumor progression are characterized by robust proliferation but minimal effector function [14], a phenotype similar to that observed in CD8+ T cells recovered from many metastatic melanoma patients. The gene discussed is CD8A; the disease is metastatic melanoma.