Abstract: Ding Cheng, Wang Ping, Liu Jiao, Li Zhao, Li Liuyu, Liu Dongyin, Zheng Junhui, Shen Hong Department of Dermatology, Hangzhou Clinical College Affiliated to Anhui Medical University, Hangzhou 310009, China （Ding C, Wang P）; Department of Dermatology, Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou 310009, China （Liu J）; Department of Dermatology, Hangzhou Third People′s Hospital, Hangzhou 310009, China （Li Z, Li LY, Liu DY, Zheng JH, Shen H） Corresponding author: Wang Ping, Email: dermwang@aliyun.com 【Abstract】 Objective To measure the of interleukin?13 （IL?13） and its receptors in mycosis fungoides （MF） lesions, and to investigate their clinical significance. Methods A total of 34 paraffin?embedded specimens of MF, which was confirmed by clinical and histopathological features, immunophenotyping and/or T?cell receptor gene rearrangements, were collected from Hangzhou Third People′s Hospital between January 2010 and March 2016. According to the tumor?node?metastasis （TNM） staging system, 5 patients were at stageⅠA, 9 at stageⅠB, 17 at stageⅡA, and 3 at stageⅡB. Ten normal skin tissue specimens served as controls. Immunohistochemical study was conducted to measure the of IL?13, IL?13Rα1 and IL?13Rα2. Results IL?13, IL?13Rα1 and IL?13Rα2 were all expressed in atypical lymphoid cells and epidermotropic lymphoid cells in MF lesions at various stages. IL?13Rα2 was highly expressed in all the MF lesions. None of IL?13 and its receptors were expressed in normal skin tissues and lymphocytes. The rates of IL?13 and its receptors in MF lesions increased along with the progression of MF. Additionally, the rates of IL?13 （10.00% ± 3.14%）, IL?13Rα1 （21.43% ± 6.88%） and IL?13Rα2 （31.14% ± 6.38%） significantly decreased in MF lesions at stageⅠ compared with those at stageⅡ （27.50% ± 11.00%, 39.45% ± 9.43%, 44.40% ± 11.15%, respectively, all P < 0.05）, but no significant differences were observed between stageⅠA andⅠB, or between stageⅡA andⅡB （P > 0.05）. Conclusion IL?13 and its receptors, especially IL?13Rα2, may be expected to serve as biomarkers for early diagnosis of MF and prediction of its biological behaviors.