Vitiligo is characterized by the selective loss of melanocytes, which in turn leads to totally amelanotic, non-scaly, chalky-white macule with distinct margins Vitiligo is the most common depigmenting skin disorder, with an estimated prevalence of 0.5-2% of the population in both adults and children worldwide Tumor necrosis factor (TNF-α), a pro-inflammatory cytokine is necessary for Th1 mediated response and immune homeostasis and the up-regulation of TNF-α can result in chronic inflammatory and autoimmune diseases . previous studies revealed a rise in transcript and protein levels of TNF-α in vitiligo patients The prime location of melanocytes, keratinocytes and fibroblasts is the epidermal microenvironment and these cells are capable of TNF-α expression and secretion TNF-α acts as an autocrine as well as a paracrine manner to suppress the melanocyte growth and proliferation ( Tristetraprolin (TTP) zinc finger protein 36 (ZFP36) is Ribonucleic acid (RNA) binding protein that preferentially binds to Adenylate-uridylate-rich (AU-rich) regions in the 3' untranslated regions (3'UTR) of target genes . Additionally, Tristetraprolin functions by destabilizing mRNAs encoding for oncogenes, cytokines (as TNFα), and chemokines involved in the inflammatory processes, by favoring their degradation and/or preventing their efficient translation The expression of proinflammatory mediator genes is tightly controlled by post-transcriptional regulation, which is mediated by a set of immune-related RNA binding proteins, such as tristetraprolin, Roquin, and Regnase

Inclusion Criteria:

• This study will include adult patients>18 yrs with non -segmental vitiligo attending the dermatology outpatient clinics at Sohag University, Egypt. A group of participants will be included as a control group.This control group will be taken from patients seeking for abdominoplasty in plastic surgery department at Sohag University Hospital.

Exclusion Criteria:

- 1)Pregnancy. 2)Patients with chronic inflammatory skin disorders. 3)Patients on antioxidants or anti-inflammatory drugs. 4)Patients on topical or systemic treatment for vitiligo in the last 4 weeks prior to enrollment in the study.

5)Patients with other autoimmune diseases as thyroiditis. lupus erythematosus and rheumatoid arthritis 6)Patients with diabetes mellitus (DM).