CYP1B1 and medullary thyroid gland carcinoma: Conversely, in MTC and in ATC CYP1B1 expression was lower than normal thyroid (MTC: median difference 0.068 [range 0.009–0.44, p < 0.0001]; ATC: median difference 0.06 [range 0.016–1.91, p = 0.0034]).