<prompt> Medullary ca of thyroid is associated with increase inCalcitoninThyroglobulinT3T4  <response>: Ans. a CalcitoninRef: Robbins 9thpg 1099-1100In Medullary Carcinoma Thyroid, serum Calcitonin is elevated.Elevated serum calcitonin also provides a marker of residual or recurrent disease.All patients with Medullary Carcinoma Thyroidshould also be tested for RET mutations, so that genetic counseling and testing of family members can be offered; 