Galectin-3 is a member of the beta-galactoside-binding protein family that plays an important role in cell adhesion, cell matrix interactions, macrophage activation, angiogenesis, metastasis, and apoptosis. Galectin-3 shows strong diffuse cytoplasmic staining in most cases of papillary thyroid carcinoma (PTC), most poorly differentiated thyroid cancers demonstrate galectin-3 protein expression while it is not expressed in anaplastic thyroid cancers. Upregulated expression of galectin-3 is involved in cancer progression and metastasis, and it is suggested that Galectin-3 may be a valuable tool to support diagnosis of parathyroid carcinoma. Galectin-3 has also been reported to play important roles in the progression of prostate cancer, and their heterogeneous expressions might be associated with different cancer subtypes.