ASAH1 and differentiated thyroid carcinoma: On the other hand, although genetic analysis of the TSHR gene in thyroid cancers supported the notion that TSHR mutations do not play a role in the pathogenesis of nonfunctioning differentiated thyroid carcinoma (48), as TSHR mediates the proliferation of thyrocytes through the TSH-AC-cAMP pathway, we cannot rule out that its constant activation by a gain-of-function mutation is a logical carcinogenic factor (48, 49).