NOTCH1 and neoplasm: The current study demonstrated that Notch-1 knockdown significantly inhibits the migratory capacity of salivary adenoid cystic carcinoma cells and reduces the number of metastatic nodules in the lung surface of mice bearing SACC xenografts, indicating that Notch-1 is implicated in the metastasis of salivary adenoid cystic carcinoma cells in vivo. Tumor progression is the process by which tumor cells acquire malignant properties, such as aggressive growth, perineural invasion, and metastasis.