EGFR and undifferentiated carcinoma: Furthermore, the overexpression of receptors, such as epidermal growth factor receptor (EGFR), are not only characteristic of anaplastic thyroid carcinoma but also of thyroid and primary thyroid carcinomas dedifferentiation or anaplastic carcinoma transformation (Fisher et al., 2013[14]; Landriscina et al., 2011[31]).