CCND1 and thyroid gland papillary carcinoma: Our results show that Cyclin D1 and CK 5/6 staining could be used in concert to distinguish between the diagnosis of papilloma (Cyclin D1 < 4.20%, CK 5/6 positive) or papillary carcinoma (Cyclin D1 > 37.00%, CK 5/6 negative).