Complete blood counts, C-reactive protein (CRP) levels, and lymphocyte subset profiles were measured, and cytokine concentrations were quantified by cytometric bead array.<h4>Results</h4>Compared with controls, COVID-19 patients exhibited marked CD4<sup>+</sup> lymphopenia and leucocytosis driven by neutrophilia and elevated immature granulocytes. The gene discussed is CD4; the disease is lymphopenia.