During the first measurement of oxytocin, it was observed that the COVID-19 group had statistically significantly (p = 0.03) lower levels of oxytocin concentrations than the non-COVID-19 group (first visit: 10.28 ± 2.88 ng/mL vs. 22.76 ± 5.09 ng/mL). The gene discussed is OXT; the disease is COVID-19.