CD4 and hyperthyroidism: In 2017, Yicheng et al. described how T CD4+ cells play a significant role in the pathogenesis of Graves’ disease, a common immuno-mediate condition; lymphocytic infiltration in thyroid gland leads to the production of autoantibody against thyroid-stimulating hormone receptor (TSH-r), which mimics the action of TSH, causing excessive thyroid hormone production and hyperthyroidism.