Author: Nat Pernick, M.D. (see Authors page)

Revised: 17 December 2015, last major update October 2013

Copyright: (c) 2003-2015,, Inc.

PubMed Search: FOXL2[title]
Cite this page: FOXL2. website. Accessed July 17th, 2018.
Definition / general
  • Forkhead Box L2; belongs to large family of forkhead FOX transcription factors (PLoS One 2012;7:e46270)
  • One of first genes expressed in female gonad development, required for proper granulosa cell differentiation during folliculogenesis
  • Expression strongly maintained in granulosa cells throughout life
  • FOXL2 expression has role in developing eyelid, associated with blepharophimosis ptosis epicanthus inversus syndrome (BPES), with or without accompanying premature ovarian failure (Mol Vis 2011;17:436, J Pediatr Endocrinol Metab 2013 Sep 13:1)

FOXL2 mutation

Uses by pathologists
  • FOXL2 mutation analysis distinguishes diffuse adult granulosa cell tumor ( 402C→G mutation present) from cellular fibroma (mutation absent) (Am J Surg Pathol 2013;37:1450, Mod Pathol 2013;26:860)
  • Note: FOXL2 staining is not specific for the FOXL2 mutation
Microscopic (histologic) images

Images hosted on other servers:

Ovary: BPES patients (figs K/L)

Images hosted on

Ovary: gonadoblastoma

Ovary: granulosa cell tumors

Pituary: normal

Pituitary adenomas

Positive staining - normal
  • Nuclear stain
  • Ovary: granulosa cells
Positive staining - disease
Negative staining
  • Ovary: most non sex cord stromal tumors
  • Ovary: gonadoblastoma - germ cells in gonadoblastoma and dysgerminoma components (Pediatr Dev Pathol 2011;14:391)
Molecular / cytogenetics images

FOXL2 gene point mutation 402C→G (C134W)