ITSN1 and laryngotracheoesophageal cleft: Although both A549 and A549 + ITSN-1s cells formed colonies, the ability of A549 + ITSN-1s cells to grow independent of anchorage was impaired compared to A549 cells (Fig. 3d); the number of colonies was 80 % lower (Fig. 3e), suggesting that ITSN-1s deficiency is an important component in the anchorage-independent growth of human LC cells.