Moreover, as immunity against SARS-CoV-2 is not limited to seroconversion, some reports have shown that B cells signatures harbor prognostic importance in non-cancer patients diagnosed with severe COVID-19, demonstrating that decreases in memory B cells and increments in antibody-secreting cells and CD19+ B cells are positively related to the severity of this disease [11]. This evidence concerns the gene CD19 and COVID-19.