TPO and autoimmune thrombocytopenic purpura: Using the ITP rat model, miR-557 was identified as a specific miRNA associated with both ITP and TPO treatment [36]; further, the authors found that the miR-557 inhibitor improved ITP by regulating apoptosis-related genes (Bcl2, Casp3, and Bax) and activating the Akt/ERK pathway.