CD38 and COVID-19: Differentially expressed genes encoded for proteins involved in NAD+ metabolism (e.g., NNMT: upregulated 4.8‐fold in the COVID‐19 group) and the immune response (e.g., IL17B: upregulated 2.8‐fold), as well as proteins known to deplete NAD+ (e.g., CD38: upregulated 2.6‐fold).