Considering the studies reporting that CD4 T cells overexpress PD‐1 in severe COVID‐19 patients and those also evoking a high expression of PD‐L1 on eosinophils,2, 5, 125 it is tempting to speculate that the interaction of PD‐1 on T cells with its ligand expressed on eosinophils will inhibit the activation of T lymphocytes and promote their exhaustion and apoptosis, explaining the lymphopenia seen in COVID‐19 patients and its persistence in severe forms.6 Here, CD4 is linked to COVID-19.