PIK3CA and chordoma: By testing the expression of key PI3K‐AKT‐mTOR markers (p‐AKT and p‐S6), common drug targets (EGFR, VEGFR, PDGFR, PD‐L1), immune cell markers (CD4, CD8) and RAB3B in this chordoma patient, we found high‐ and co‐expression of RAB3B and p‐S6 (S235/236), as well as EGFR (Figure 8C–F; Figure S14G–L, Supporting Information).