PIK3CA and chordoma: Mechanistically, RAB3 isoform‐dependent activation of AKT/GSK3β pathway has been reported in several studies.[19] In addition, RAB3C could modulate cancer cell migration through IL‐6‐JAK2‐STAT3 axis.[20b] To investigate the tumorigenic mechanism of RAB3B in chordoma, RNA‐seq, and western blotting were applied and a strong correlation was found between RAB3B and PI3K‐AKT‐mTOR signaling, especially mTORC1 signaling.