IFNG and obesity due to melanocortin 4 receptor deficiency: In addition, obesity was linked to a higher IFN-γ response to SARS-CoV-2 S1, a higher CD8 + T cells proliferation to S1, S2, ORF 7 and 8, and an increased CD8 IL-2 response to spike (Fig. 5B, Supplementary Tables S2b, S2d, and S2f).