Recently, two independent studies, one from Memorial Sloan Kettering Cancer Center (MSKCC, New York, NY) by Alzumaili et al10 and the other from Royal North Shore Hospital, Sydney, Australia, by Fuchs et al,11 independently identified mitotic index (MI), tumor necrosis, and/or Ki67 proliferative index as prognostic histologic features in MTC, and subsequently proposed two different but broadly similar histologic grading schemes for MTC. Here, MKI67 is linked to neoplasm.