MPV tends to increase in response to TPO stimulation as larger, more immature platelets are released, leading to more rapid depletion of the rapidly differentiated, small, megakaryocytes.7 The association of increased MPV and thrombocytopenia with mortality in one study of sepsis in a PICU setting suggested that in septic children, bone marrow exhaustion may represent an almost preterminal event.14 This evidence concerns the gene TPO and Thrombocytopenia.