Expression of the Hippo pathway members Yes-associated protein 1 (YAP1) and LATS1/2 (large tumor suppressor 1/2) in parathyroid tissues. Immunohistochemistry analysis for total YAP1. Representative images showed immunostaining in normal parathyroid glands from normocalcemic patients (a,b), benign parathyroid adenomas (c,d), parathyroid carcinomas (e,f). (c) Black arrow indicates normal parathyroid cells of the parathyroid gland rim surrounding the parathyroid adenoma. (e) Section of parathyroid carcinoma from a patient harboring a germline inactivating multiple endocrine neoplasia type 1 (MEN1) gene mutation. Magnifications are indicated in each panel; the inserts show enlarged details. (g) Negative controls. (h) Quantification of nuclear YAP1 staining as a percentage of positive parathyroid cells; each dot is a case; lines, mean, and SD; PaNs, parathyroid normal glands from normocalcemic patients; PAds, parathyroid benign adenoma; PCas, parathyroid carcinoma; black or grey circles, PCas harboring cell division cycle 73 (CDC73) or MEN1 inactivating mutations, respectively; white circle, PCa harboring CDC73 and MEN1 wildtype alleles; *, p = 0.024; **, p = 0.012 by one-way ANOVA corrected for multiple comparisons. (i) Western blot analysis of LATS1, LATS2, phosphorylated YAP1, and total YAP1 expression, in total protein extracts from a series of seven parathyroid adenomas (PA), compared with total protein extracts from human embryonic kidney 293A (HEK293A) cells. GAPDH was a loading control.