L1CAM and neoplasm: However, an initial phase I clinical trial in humans for recurrent/refractory neuroblastoma (NCT02311621) revealed the development of clinically relevant, albeit transient, skin rash and hyponatremia, potentially resulting from on-target, off-tumor CAR T cell L1CAM targeting in the skin, kidney, or pituitary gland (Pinto et al. 2018).