Humoral responses to tumour xenografts in ALS‐treated mice

An isotopic antiglobulin technique was used to study the humoral response to a hamster tumour grafted into ALS‐treated or normal mice. Approximately 50% of ALS‐treated animals fail to reject the tumour after cessation of ALS treatment. All ALS‐treated animals show a delayed humoral response compared to controls but in those animals which fail to reject tumours, a high level of serum antibody is maintained even in the presence of a large tumour mass.