Regarding the immunohistochemical analysis, there was a statistically significant difference in the expression of the following markers, with higher concentrations in control group B compared to COVID-19 group A: IL-6 (p < 0.0001), IL-18 (p = 0.002), CASP-9 (p < 0.0001), and HIF (p = 0.0327). The gene discussed is IL18; the disease is COVID-19.