CD4 and differentiated thyroid carcinoma: Abstracts of these articles were screened and 7 (21, 26–31) were excluded according to the abovementioned criteria [4 reported small series (26, 28–30), 1 included patients showing the effect of switching T4 treatment in patients, which had already reached normal TSH with traditional tablet formulation (27), one described the use of a non-pharmaceutically produced liquid preparation (31), one enrolled only differentiated thyroid carcinoma patients (21)].