Recently, IgGs carrying CAT activity were found to be significantly increased in non-pregnant patients who had recovered from COVID-19 compared to both healthy women and patients vaccinated with the recombinant Sputnik V vaccine, opening up the hypothesis that COVID-19 infection may stimulate the production of antibodies with enzymatic activity that degrades hydrogen peroxide and counteracts ROS production [43]. The gene discussed is CAT; the disease is COVID-19.