FOXL2 and ovarian granulosa cell tumor: First, the small number of cases subjected to mRNA sequencing could have resulted in a type II/β-error in the search of a highly-recurrent pathognomonic event; however, by the sequencing of five samples we should have been able to identify a recurrent event (ie with a prevalence similar to FOXL2 mutations in granulosa cell tumours of the ovary 52) with 97% statistical power.