Relation of polymorphisms VEGF (+405G>C) and TNFα (-308A>G) with the embryo implantation in Cubans patient undergoing in vitro fertilization oleh Francisco Sotomayor Lugo, Beatriz Marcheco Teruel, Kenia Rodríguez Martínez, Alejandro Esperón Álvarez, Ahmed Menocal Alayón, José Alberto Almaguer Almaguer, Ixchel López Reyes, Rosa María Flores Sánchez, Yoandra Crespo Ferrán, Vivian Veiga Loyola