“…IGFBP2, a key member of the IGF family, is present in follicular fluid and subject to dynamic changes during follicle growth and maturation (Spitschak & Hoeflich, ). Previous reports have confirmed the involvement of genetic variants of IGFBP2 in reproductive traits or litter size in different pig populations (An et al, ) and age at first calving in dairy cattle (Clempson, Pollott, Brickell, & Wathes, ). Moreover, mRNA expression analysis showed that IGFBP2 mRNA level was upregulated in the endometrium of pregnant mares (Merkl et al, ) and of pigs (Ostrup, Bauersachs, Blum, Wolf, & Hyttel, ) on day 14 of pregnancy.…”