To identify candidate mTOR-interacting molecules, we performed an anti-Flag immunoprecipitation (IP) followed by mass spectrometry (MS)-based proteomic analysis in 293T cells overexpressing Flag-tagged mTOR. We identified P4HA2 binding proteins with anti-HA IP followed by (MS)-based proteomic analysis in 293T cells overexpressing HA-tagged P4HA2. To speculate that mTOR can be hydroxylated by P4HA2. We used 293T cells overexpressing Flag-mTOR, Flag-mTOR/HA-P4HA2, and Flag-mTOR/HA-P4HA2-overexpressing cells treated with EDHB, we conducted an anti-Flag IP to capture and enrich mTOR protein, and the immunoprecipitates were subjected to MS analysis.