Examining the role of CD19 in the context of infectious diseases, we found no differences between patients with CD19 levels lower and higher than 200 cells/mm3, with a mean of 5.00 ± 4.51 (IQR, 2.13–7.86) and 5.75 ± 4.78 (IQR, −1.86 to 13.37), respectively. The gene discussed is CD19; the disease is infectious disease.