It is a bit intriguing to note that HNF1α, a tumour suppressor gene, whose abnormal expression could enhance tumorigenesis, is inactivated in 35-50% of all liver adenomas, which are, like FNH, much more frequent in women taking oral contraceptives: moreover germline mutation of HNF1α can be associated with maturity onset diabetes of the young 3 (MODY3). This evidence concerns the gene HNF1A and maturity-onset diabetes of the young type 3.