For example, the inhibition of mutant-EGFR in lung adenocarcinoma cells or mutant-BRAF in thyroid cancer cells was shown to induce the secretion of IL6 and the subsequent activation of STAT3, and in both cases, blocking the STAT3 function largely prevented the emergence of drug-tolerant cells [13,14]. Here, STAT3 is linked to thyroid gland carcinoma.