Compared to the plain group, type III had lower preoperative Ctn values, lower preoperative CEA values, lower proportion of calcified MTC lesions, lower proportion of nodular goitre, higher proportion of thyroiditis, fewer central lymph node dissections, fewer central lymph node metastases, fewer lateral neck lymph node metastases, higher proportion of N0 stage and lower Ki67. This evidence concerns the gene MKI67 and thyroiditis.