TG and thyroid cancer: Tg is the most sensitive marker for detecting recurrence of differentiated thyroid cancer; however, the presence of antithyroglobulin antibody (TgAb) interferes with measurement of Tg; therefore, development of Tg assays with limited or no interference by TgAb and development of methods for clearing of TgAb prior to measurement of Tg are warranted [1, 3, 4].