Germline changes like single-nucleotide variants (SNVs) and/or copy number variations (CNVs) in several genes have been implicated in familial isolated PAs—FIPA (AIP and GPR101 genes) (6, 7), familial syndromic PAs (MEN1, CDKN1B, PRKAR1A, PRKACB, SDHx, MAX, NF1, DICER1, and TSC2, among others), and sporadic PAs (AIP, GPR101, and CABLES1). Here, GPR101 is linked to familial isolated pituitary adenoma.