IL6 and COVID-19: Augustin et al. (2021) evaluated post-COVID syndrome in outpatients, but in order to correlate clinical symptoms with IgG antibodies, they did not evaluate molecular markers of inflammation. Cytokine IL-6 has been proposed as a potential mediator of neuropsychiatric symptoms of long COVID-19, possibly related to its persistence (Kappelmann et al., 2021).