MPL and hematocrit: As a TPO membrane receptor, c‐Mpl has been proven to be involved in hematopoietic stem cell development, megakaryocyte differentiation, and platelet production.[10] The abnormal expression of c‐Mpl on the cell surface is an established feature of several diseases (CAMT, HT, myeloproliferative neoplasms, and others),[12, 13, 15] but there is no reported evidence on the status of c‐Mpl on the MK cell surface in ITP.