“…Many factors secreted within the pig uterus are important during the critical period of conceptus elongation and implantation, including insulin‐like growth factors (IGFs) (Green, Simmen, & Simmen, ; Jeong, Song, Bazer, & Kim, ), IGF‐binding proteins (Geisert, Chamberlain, Vonnahme, Malayer, & Spicer, ; Lee, Green, Simmen, & Simmen, ), epidermal growth factor (EGF) (Jeong, Jung, Bazer, Song, & Kim, ; Kennedy, Brown, & Vaughan, ; Vaughan, James, Pascall, & Brown, ), heparin binding‐EGF (Kim et al, ), transforming growth factor beta (TGFB) (Jaeger et al, ; Massuto et al, ), fibroblast growth factor 7 (FGF7) (Ka et al, , ), vascular endothelial growth factor (VEGF) (Kaczmarek et al, ), colony stimulating factor 2 (CSF2) (Jeong, Kim, Bazer, & Song, ), leukemia inhibitory factor (LIF) (Kaczmarek et al, ), and interleukin 6 (IL6) (Anegon et al, ; Modric, Kowalski, Green, Simmen, & Simmen, ). Endometrial secretion of FGF7, LIF, and IGF‐1 are specificity enhanced before and after elongation (reviewed by Geisert et al, ).…”