ZBTB1 and congenital T-cell immunodeficiency: Of note, despite the similar extent of T-cell deficiency, ZBTB1-knockout mice have increased numbers of short-term HSCs, multi-potent progenitors and CLPs (27), while scanT mice with a single substitution of the conserved cysteine (C47R) in the BTB domain of ZBTB1 do not (28).