Background: Papillary thyroid carcinoma (PTC) is one of the most prevalent endocrine malignancies, with complex pathogenesis. Transforming growth factor-β-activated kinase 1 (TAK1)-binding protein 3 (TAB3) is implicated in cell division and metastasis. The proviral integration site for Moloney murine leukemia virus 1 (PIM1) is a key player in carcinogenesis and overexpressed in cancer tissues. However, to our knowledge no previous study assessed the role of TAB3 in PTC and only few studies assessed  the role of PIM1 in PTC pathogenesis.
Objectives: The current research aimed to assess the protein expression of TAB3 and PIM1 in PTC specimens compared to the adjacent non-neoplastic thyroid tissues and to assess the correlation between their expression and the clinic-pathologic features of PTC. Then, to assess the correlation between TAB3 and PIM1 expression in PTC.
Patients and methods: TAB3 and PIM1 expression were immunohistochemically examined in fifty specimens of PTC and their adjacent non-neoplastic thyroid tissues.
Results: TAB3 and PIM1 were significantly overexpressed in PTC than in adjacent non-neoplastic tissues (p value < 0.001, each).  TAB3 expression was significantly higher in older age and higher clinical stage (p= 0.003 and 0.028 respectively). A significant higher PIM1 expression was detected in PTC specimens with extrathyroidal extension (p=0.047). A significant positive correlation between TAB3 and PIM1 in PTC was detected (p=0.036).
Conclusion: The current results suggested that TAB3 and PIM1 may contribute to PTC pathogenesis and progression and may be suggested to have a promising therapeutic role.