Consistently, it was demonstrated that an increased CD4‐to‐CD8 ratio identifies a population of elders with impaired physical and mental performance, and lower reactivity against CMV antigens,32 and some studies have suggested that the CD4‐to‐CD8 T cell ratio is a risk factor for COVID‐19 critical illness and ICU admission.29, 33, 34. The gene discussed is CD4; the disease is COVID-19.