IL17A and myeloid sarcoma: In a search for a mechanism of lesion induction by Th17 cells in MS, it was shown that in addition to IL-17 production and its proinflammatory action, up to 60% of cells expressing IL-17 and also IL-22 expressed the cytolytic enzyme called granzyme B. Furthermore, when granzyme B-Th17 cells were added to neuron-enriched cultures, a significant number of neurons underwent programed cell death [31–34].