RTP801L represents a unique gene target for hypoxia-inducible factor-1 (HIF-1) that may regulate hypoxia-induced pathogenesis; down-regulation of the mTOR pathway activity by hypoxia requires de novo mRNA synthesis and correlates with increased expression of RTP801L. The present invention relates to screening systems utilizing RTP801L and/or RTP801L interactors and/or RTP801L biological activity, and to the potential drugs and methods of treatment identified by such screening systems.