Thus, the goal of the present text was the evaluation of the changes in the profile of expression of irisin, ghrelin, and titin and also the evaluation of the methylation profile in the carcinoma tissue as well as the blood of patients with HNSCC depending on their nutritional status before treatment, during treatment, and 6 months after the completion of chemotherapy. Here, FNDC5 is linked to head and neck squamous cell carcinoma.