CD4 and autoimmune disease: When induced with antigens and cytokine networks, naïve CD4+ T cells are converted into different phenotypes such as Th1, Th2, Th17, and Treg.57 Treg cells are defined by the expression of a specific transcription factor called FOXP3, which is playing a unique role in immune system regulations.58 Moreover, humans with FOXP3 mutations develop autoimmune disorders like polyendocrinopathy and enteropathies.59,60 EZH2 is a histone methyl transferase that interacts with FOXP3 target genes in immune regulatory pathways.