The expression of the Hippo cofactor YAP1 was investigated by immunohistochemistry in formalin-fixed paraffin-embedded (FFPE) sections from normal parathyroid glands (PaNs, n = 4), parathyroid adenomas (PAds, n = 11), and parathyroid carcinomas (PCas, n = 6) (Figure 1). Here, YAP1 is linked to parathyroid gland adenoma.