['The response of tumors to chemotherapy (CHT) exhibits wide individual variations.', 'We examined the incidence of polymorphic TNF genes in 61 patients treated for Hodgkin lymphoma.', 'During treatment, the patients were divided as responders or non-responders, depending upon the amount of CHT required for a clinical eradication of the tumor. The incidence of TNFa4, a microsatellite allele associated with low TNF production in leukocytes, was significantly higher in responders than in non-responders (25.7% vs 0 %, p=0.04). We also examined the incidence of tumor relapses 2-5 years after treatment. The incidence of TNFa4 was also significantly higher in patients with relapses, than in those without relapses (41.1% vs 9.3%, p=0.007).'] Is polymorphic tumor necrosis factors microsatellite TNFa4 associated with resistance of Hodgkin lymphoma to chemotherapy and with replapses after therapy?