A retrospective study of elderly patients with either intermediate or high grade NHL treated with combination chemotherapy (i.e. CHOP) in Peru found that there were 35 deaths among the 267 patients treated (13.1%); the majority of these treatment related deaths were secondary to infection.[23] A comprehensive and systematic review of 17 randomized controlled trials revealed that the use of prophylactic granulocyte-colony stimulating factor (G-CSF) decreased the risk of febrile neutropenia and early death–including infection related mortality. This evidence concerns the gene CSF3 and infection.