When the analysis was performed in the whole cohort (probands and relatives), the association of PHPT and pituitary tumors, as well as the presence of malignant tumors, was significantly more common in patients with S-MEN1 than with F-MEN1 (P<0.001 and P = 0.02, respectively) (Fig 1B). Here, MEN1 is linked to pituitary tumor.