The forkhead factor FOXL2: A novel tumor suppressor?

FOXL2 is a gene encoding a forkhead transcription factor, whose germline mutations are responsible for the blepharophimosis ptosis epicanthus inversus syndrome. We have previously shown that expression levels of FOXL2 in a series of juvenile ovarian granulosa cell tumors (OGCTs) were markedly reduced. More recently, a whole-transcriptome ‘next-generation’ sequencing study has identified the somatic mutation p.Cys134Trp as recurring in adult OGCTs. This mutation may thus provide the tumor with either a striking proliferative potential or increased survival abilities. These studies of FOXL2 in OGCTs suggest that it may act as a tumor suppressor gene. This is in line with the fact that other forkhead transcription factors have already been involved in the etiology of cancer. Indeed, an in-depth review of existing data on FOXL2 reveals that its target genes and molecular partners can often be linked to cancer progression.