Here we demonstrate that the therapeutic effects of indirubin may be achieved through the regulation of CD4+ T‐cell homeostasis in ITP by promoting the development and function of Tregs as well as reducing the activation of effector T cells via a PD1/phosphatase and tensin homolog (PTEN)/AKT signalling pathway. Here, PTEN is linked to autoimmune thrombocytopenic purpura.