The SARS-CoV-2-specific response in the IgDlo B cell (CD20+ CD38int-lo) population was divided between conventional (CD27+) and double negative (CD27-) memory B cells, with both populations displaying similar kinetics in COVID-19-naïve PAD patients and healthy donors (Figures 1C, D; S2C, D). This evidence concerns the gene CD27 and COVID-19.