Twin-to-Twin Transfusion Syndrome, also known as twin to twin transfusion syndrome, is related to polyhydramnios and tricuspid valve insufficiency. An important gene associated with Twin-to-Twin Transfusion Syndrome is PGF (Placental Growth Factor), and among its related pathways/superpathways are Angiogenesis (CST) and VEGFR1 specific signals. The drugs Racepinephrine and Lidocaine have been mentioned in the context of this disorder. Affiliated tissues include heart and brain.