Utilizing lentiviral vectors (pLenti-Fgfr2_215_C361Y-EGFP and control pLenti-EGFP, Fig. S6f) developed in our previous study33 to mimic the Fgfr2 mutation underlying Crouzon syndrome, we additionally engineered a Twist1 knockdown lentiviral vector (pLenti-Twist1_shRNA-EGFP, Fig. S6c) to simulate the haploinsufficiency of Twist1 mutation characteristic of Saethre-Chotzen syndrome34. The gene discussed is FGFR2; the disease is Crouzon syndrome.