Previously, we reported an increase in carboxypeptidase A3 (CPA3) levels in the serum of severe COVID-19 patients, which was a good predictor of disease severity [12]; this suggests that MCs not only participate in SARS-CoV-2 infection pathogenesis but might also be involved in sequelae of post-acute COVID-19 syndrome. This evidence concerns the gene CPA3 and COVID-19.