Through bioinformatics analyses, Shi et al. [15] identified 52 commonly differentially expressed genes among Alzheimer's disease, Parkinson's disease, and COVID‐19, with 5 hub genes highlighted in the protein–protein interaction network: GAD2 (Glutamate Decarboxylase 2), SST (Somatostatin), TAGLN3 (Transgelin 3), SYP (Synaptophysin), and KCNJ4 (Potassium Inwardly Rectifying Channel Subfamily J Member 4). The gene discussed is GAD2; the disease is COVID-19.