EIF4EBP1 and neoplasm: In contrast to the apparent redundancy of TFEB and TFE3 for tumor growth in vivo, in vitro results (Fig. 4a) suggested that single TFEB or TFE3 KO may be sufficient to dampen the phosphorylation of direct mTORC1 substrates (p-4E-BP1 and p-p70S6K).