MMP2 and neoplasm: Consistent with the involvement of Rab40b in mediating transport of MMP2 and MMP9, which have been implicated in vasculogenesis, there was a significant increase in apoptosis in large KD tumors as compared to control (Fig. S2D,E), likely caused by the lack of tumor vascularization in early tumorigenesis, which could lead to hypoxia and eventually apoptosis.