In addition, some studies reported an increase in the serum levels of IL-6 (50, 72), a cytokine with both pro-inflammatory and anti-inflammatory properties, after administration of hMSCs while another study reported an increase in the levels of GM-CSF (71), a cytokine usually employed to stimulate the production of leukocytes in order to prevent neutropenia after chemotherapy. Here, CSF2 is linked to neutropenia.