CD38 and COVID-19: Activation of the T‐cell compartment in COVID‐19 convalescent patients was also evident when we examined CD38 co‐expression on CD3+ T cells (4.6 ± 3.6 × 106/L vs 3.5 ± 2.7 × 106/L; P = .0275; 0.27 ± 0.24% vs 0.19 ± 0.14%, P = .0051), which is another important activation antigen and also an endothelial adhesion molecule known for its upregulation on virus‐specific T cells.38, 39