Besides a modest change in the CD4+ memory T cell subsets before therapy, we suggest a role of the baseline frequency of classical monocytes in discriminating patients with distinct clinical outcomes, similar to what has been described for the predictive value of the frequency of peripheral CD14+CD16−CD33+HLA-DRhi monocytes in anti–PD-1 blockade therapy for patients with melanoma (39). The gene discussed is CD4; the disease is melanoma.