To determine whether BHLHE40 regulates late metastatic events after entry of tumor cells into the blood stream, we examined the effect of BHLHE40-KD on the ability of tumor cells to survive circulation and colonize in the lungs using an experimental metastasis model, in which tumor cells were delivered into the blood stream through tail vain injection to bypass the initial steps of metastasis such as migration and intravasation. Here, BHLHE40 is linked to neoplasm.