Two research groups, including Cohen MS et al. and De Groot JW et al., reported that imatinib inhibits both cell proliferation and RET phosphorylation in medullary thyroid carcinoma (MTC), a malignancy of C Cells of the thyroid gland associated with gain-of-function mutations in RET [30,31]. The gene discussed is RET; the disease is medullary thyroid gland carcinoma.