Abstract: Provided are methods, kits and compositions related to toxicity associated with administration of cell therapy for the treatment of diseases or conditions, e.g., cancer, including methods for use in predicting and treating a toxicity. In some embodiments, the toxicity is a neurotoxicity or cytokine release syndrome (CRS), such as a severe neurotoxicity or a severe CRS. The methods generally involve detecting a parameter of a biomarker or individually a parameter of each biomarker in a panel of biomarkers, such as a concentration, amount or activity, and comparing the detected parameter to a reference value for the parameter to determine if the subject is at risk for developing the toxicity, such as neurotoxicity or CRS or severe neurotoxicity or severe CRS.