GZMB and neoplasm: This suggests that the synthesis of this protease is not markedly modulated by environmental factors, and that it can be responsible for relatively efficient functioning of NKs after achieving remission, but still during the treatment, as it was postulated by many authors.22,56,57 In contrast, it has been reported in patients with MDS and AML significantly lower percentage of NK expression of granzyme B in relation to the control group.43 Perhaps this is due to a different tumor biology.