Among them, HMG20B, as a DNA binding gene, has been verified to play the role of erythroid differentiation inhibitor by downregulating differentiation-related genes (such as Hrasls3) and activating differentiation inhibitors (such as Gfi1b) in mice.[25] Therefore, HMG20B may be engaged in the clinical manifestation of anemia in TS patients. Here, GFI1B is linked to Timothy syndrome.