Various studies have revealed the association of E-proteins with their negative regulators (ID family) in the development of diseases such as Rett syndrome (TCF3, ID1-4), atherosclerosis (TCF3, ID3), Diamond Blackfan anemia (TCF12, ID2), polycystic kidney disease (TCF3, ID2), and Burkitt’s lymphoma (TCF3, ID3) [58,59,60,61,62]. Here, TCF3 is linked to atypical Rett syndrome.