MEN1 and parathyroid gland adenoma: Two additional miRNAs, miR-4258 and miR-664a-3p, that had been found to be significantly differentially expressed in LOH MEN1 parathyroid adenomas vs. non-LOH parathyroid adenomas [17] were excluded from the present study, since a preliminary screening of a pool of serum samples from MEN1 patients and a pool of serum samples from HCs performed in our laboratory showed no significant difference in the circulating levels of these two miRNAs between the two groups.