ABI3 and thyroid gland follicular carcinoma: To identify whether the transcriptional repression of ABI3 in thyroid carcinomas results from DNA methylation in the promoter region of the gene, ABI3 expression was assayed in thyroid follicular carcinoma cell lines (FTC 238, FTC 236, FTC 133 and WRO) following treatment with the demethylating agent 5-aza-2′-deoxycitidine (5-aza-dC).