Treatment with the DNA-demethylating agent 5-Aza-2′-deoxycytidine induced promoter demethylation of REC8, which was otherwise normally hypermethylated by the genetically activated PI3K pathway, and restored its expression in 4 of the 5 thyroid cancer cell lines tested (Figure 3B). Here, PIK3CA is linked to thyroid gland carcinoma.