TFAP2B and cystic kidney disease: In contrast, heterozygosity of Tfap2b in nephron progenitor cells causes progressive distal convoluted tubule abnormalities with associated renal fibrosis and cysts; whereas complete loss abolishes the development of distal convoluted tubules, and causes renal cysts, fibrosis, and early postnatal death (Marneros, 2020; Lamontagne et al., 2022).