Indeed, elevated levels of proinflammatory cytokines such as TNF-α [24] and cytotoxic/helper T lymphocyte infiltration [26] were observed in the olfactory epithelium of patients with COVID-19, raising the possibility that an indirect contribution by immune cell responses against the olfactory epithelium may participate in anosmia in COVID-19 patients. Here, TNF is linked to Kallmann syndrome.