The course of COVID-19 is determined by various factors. Studies worldwide have shown a correlation between changes in the expression profile and the severity of the disease. Thus, an in-depth study of differentially expressed genes will allow a more detailed investigation of the metabolic changes occurring in the background of coronavirus infection. The technique of RNA sequencing and subsequent bioinformatics analysis is suitable for such research tasks. In our study, we compared groups of samples from patients with mild and severe disease course and identified a number of differentially expressed genes. These genes are involved in metabolic pathways responsible for immune response, signaling, intercellular communication, metabolism of various compounds etc. We then identified master regulators whose function and role in pathways enriched by differentially expressed genes makes them potential targets for biochemical and meta-studies.