['Recent data suggest that mutations in the aryl hydrocarbon receptor interacting protein gene (AIP) are associated with pituitary adenomas. AIP is considered to be a tumour suppressor gene.', '110 Caucasian patients living in Germany with pituitary adenoma (55 hormone secreting, 55 non-functioning) were examined for AIP mutations.', "Three patients (2.7%) harboured an AIP germline mutation. A heterozygous mutation, R16H (c.47G>A), was found in two patients and a heterozygous G>C change in the 3'UTR, 60 bp downstream of the termination codon, in one patient. All three patients suffered from non-functioning adenoma. Additionally, a silent polymorphism, D172D (c.516C>T), was found in 3 patients with non-functioning adenoma, in 2 patients with prolactinoma and in one patient with acromegaly."] Are aryl hydrocarbon receptor interacting protein gene ( AIP ) mutations rare in patients with hormone secreting or non-secreting pituitary adenomas?