While these differences may stem from lower susceptibility to SARS-CoV-2 in children (e.g. due to reduced ACE2 expression in the nasal epithelium [28,29]), they could also arise from reduced exposure (e.g. due to school closures) or a milder clinical course of the infection coupled with a distinct immune response characterised by absence of anti-nucleocapsid IgG antibodies [30]. The gene discussed is ACE2; the disease is infection.