RALBP1 and cancer: RalBP1 is tightly linked to suppression of apoptosis and promotion of tumorigenesis.20,21 Apoptotic cancer stem cells use RalBP1 in dynamin-dependent endocytosis to suppress apoptosis during the blebbishield emergency program.5 Although VHL is generally portrayed as a tumor suppressor,11 VHL is also known to play an oncogenic role by inhibiting apoptosis15 and to regulate dynamin-dependent endocytosis.12 Hence, we examined the expression of RalBP1 and VHL in 30 human bladder cancer cell lines and in 12 human non-bladder cancer cell lines from hematological and solid tumor types.