Biotin-labeled LOC644656 sense-, antisense-conjugated avidin magnet beads or empty magnet beads (Mock) were used for RNA pull-down using whole cell lysates of human embryonic stem cells. LOC644656 complexes were pulled-down and then separated by SDS‒PAGE. Bands were removed from the gel, and trypsin-digested samples were subjected to liquid chromatography-tandem mass spectrometry (LC-MS/MS) using an Orbitrap Velos Pro (Thermo Scientific). MS/MS dataset analysis was performed using the Mascot software program (Matrix Science).