15 genes were induced only in patients of Group 3 relative to controls. These genes included those associated with leptin (LCK, IRF1, VCAM1, SNAI1), MHC‐class I and II (HLA‐A, HLA‐C, HLA‐DQA2), and immune regulatory functions (IL10, CD40, NT5E, CORO1A). Considering only the 14 COVID‐19 patients, 17 genes were exclusively associated with BMI; among them those associated with cytokine signaling and immune response (CD40LG, CXCR2, ADORA2A, PIK3CD, and CD37) and receptors for the Fc region of IgG molecules (FCGR3A and FCGR3B) were downregulated. Here, CD40 is linked to COVID-19.