Conventional FoxP3+ regulatory T cells suppress the activation and proliferation of effector T cells and are critical to prevent autoimmunity and may prevent rejection in solid organ transplantation.35 Due to the plasticity of helper T cells, Tregs can turn on Bcl6 and can express the follicular homing receptor CXCR5, resulting in Tfr phenotype.36, 37 Only a subset of Treg, 10% to 15%, can inhibit Tfh cells in murine and human lymphoid tissue.36, 37 Tfr cells share phenotypic characteristics of both conventional FoxP3+ Tregs and Tfh cells by expressing FoxP3, Bcl6, CXCR5, PD‐1, SAP and CD28. The gene discussed is BCL6; the disease is Autoimmunity.