In the beginning, when infection occurs, the release of many inflammatory cytokines (such as interleukin‐1 (IL‐1), IL‐3 and IL‐6, and tumor necrosis factor‐α (TNF‐α)) increases, leading to the increase of thrombopoietin and the expression of young platelets in the blood stream,9, 32 which causes the increase of MPV. The gene discussed is IL3; the disease is infection.