Given that women with unexplained infertility show decreased H19 expression in their eutopic endometrium (Korucuoglu et al, 2010) and that H19 regulates let-7 (Kallen et al, 2013) which targets Igf1r (Zhu et al, 2011), we wished to determine the physiological role of H19 in the endometrium and its relationship with the IGF signaling in endometriosis. The gene discussed is IGF1R; the disease is endometriosis.