CD4 and Oral ulcer: Freeze-dried powder from G. lucidum mycelia (FDPGLM) in high doses reduced the number and area of oral ulcers induced in rats, increasing significantly the serum levels of TGF- β 1, which in turn promoted cicatrisation of the lesions, increased expression of the Foxp3 gene and improved levels of the lymphocytes CD4+ and CD25+ (40).