In order to circumvent the effect of Rab40b on tumor size, we analyzed metastasis in lungs from mice with size-matched large tumors over an extended time and found that there was no noted difference in number of disseminated human cells (Rab40b KD, 31±3.3 cells; control, 20±6.6 cells; mean±s.e.m). Here, RAB40B is linked to neoplasm.