Although we favor suboptimal T cell stimulation as a driver of incomplete differentiation in our model, we cannot rule out the possibility that CD8+ T cell differentiation is directly suppressed by tumor‐derived or tumor‐associated factors in the microenvironment of regional LN, as nontumor immunoregulatory cell populations that accumulate in sentinel LN or suppressive factors that drain to these sites may create a local milieu that is inhospitable to T cell activation even prior to LN invasion by the tumor. The gene discussed is CD8A; the disease is neoplasm.