L1CAM and neoplasm: L1CAM IHC was performed in all 452 cases, of which results for ESMO non-high-risk tumours were previously reported.23 L1CAM was completely negative (score 0) in 320/452 (70.8%) tumours, showed minimal staining (score 1, 1–10% of tumour cells) in 35/452 (7.7%), and positive staining ( ≥ 10% of tumour cells) in 97/452 (21.5%) tumours.