CREB1 and thyroid gland papillary carcinoma: Especially in papillary thyroid carcinoma with the fusion of CCDC6 and RET, CCDC6 has been reported to interact with CREB1 (cAMP response element binding protein 1, a protein involved in the regulation of thyroid cell proliferation) and repress its transcriptional activity by recruiting histone deacetylase 1 and protein phosphatase 1 proteins at the CRE site of the CREB1 target genes 28.