Among the various interleukins involved in inflammatory responses, interleukin-1 (IL-1), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-18 (IL-18) have been extensively studied in periodontal medicine due to their potential shared pathogenic roles in both periodontitis and systemic inflammatory diseases. Here, IL4 is linked to periodontitis.