CD40LG and COVID-19: We have previously shown a cumulative prevalence of COVID-19 of ∼3.2%–3.8% in Wuhan, with estimates based on a survey of serum IgM and IgG levels collected between 9 March 2020 and 10 April 2020 from 17 368 residents in the city.1 Based on another survey of 16 101 community subjects who underwent health check-ups between 15 March 2020 and 7 May 2020 in another hospital in Wuhan, a total of 709 (4.4%) subjects was found to be seropositive for either IgG (n = 539) or IgM (n = 64), or both IgG/IgM (n = 106) against SARS-CoV-2.