CD44 and neoplasm: Increasing evidence suggests that stem‐like properties of PTC cells play an essential role in the progression of different diseases, such as tumor metastasis, initiation, invasive growth, and so on.10 For example, Ahn et al11 showed that the percentage of CD44+/CD24− cells was higher in aggressive recurrent PTC, meanwhile, as a stem cell marker, POU5F1 was found upregulated in the CD44+/CD24− subpopulation and tumorigenic thyrospheroid cells.