TNF and Hand-foot syndrome: Pro-inflammatory macrophages stimulate the production of mediators like TNF and IL-1β, which are critical for supporting HF regeneration.49, 50, 51 In addition to macrophages, T cells can differentiate into specialized subsets, such as T helper cells, to regulate the skin's local immune environment and drive the immune response through the Th1/Th2/Th17 paradigm.52, 53, 54 For instance, Tregs promote HFs by mitigating the potentially harmful effects of the innate immune system, specifically by inhibiting the activity of macrophages.55