As shown in Fig. 3a, b, a SARS-CoV-2 S-specific CD4+ T cell response (OX40+CD137+) was detected in 17 of 20 individuals recovered from COVID-19 with symptoms (fisher’s exact P = 0.030 vs healthy controls, 4 of 10 individuals), and a CD4+ T cell response to M and N was also detected in individuals recovered from symptoms, with 9 (45%) and 15 (75%) individuals recovered from COVID-19 with symptoms, respectively (Fig. 3b), which were not significantly different than healthy controls (fisher’s exact P were 0.246 and 0.045 vs healthy controls, respectively). Here, TNFRSF9 is linked to COVID-19.