Figure S3 presents results obtained with representative samples from COVID‐19 patients and controls when tested for IgG, IgM, and IgA reactivity indicating that IgG, IgM, and IgA responses are directed to different SARS‐CoV‐2 antigens/epitopes, which would explain the lack of correlation of specific isotype responses (Figure S2A). Here, CD79A is linked to COVID-19.