A commentary discusses how these results should be interpreted and suggests that although this trial did not meet its primary endpoint, to conclude from this single study that rituximab is not active in primary CNS lymphoma neglects the total body of clinical evidence. It points out the established benefit for rituximab in systemic diffuse large B-cell lymphoma and results from both randomised trials in primary CNS lymphoma, and believes rituximab should remain a component in the treatment of patients with primary CNS lymphoma.